NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities- As you have learned in previous classes that expressions are formed from variables and constants. This chapter will introduce you to the application of algebraic terms and variables to solve various problems. NCERT solutions for Class 8 Maths chapter 9 Algebraic Expressions and Identities will give you a detailed explanation for every problem of this chapter. Algebra is the most important branch of mathematics which teaches how to form equations and solving them using different kinds of techniques. Important topics like the product of the equation, finding the coefficient of the variable in the equation, subtraction of the equation and creating quadratic equation by the product of its two roots, and division of the equation are covered in this chapter.

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You will find the questions related to these topics in NCERT solutions for Class 8 Maths chapter 9 Algebraic Expressions and Identities which will make your task easy while solving the problems. As it is a new concept, you may find difficulties while dealing with algebraic parts of mathematics but if you practice questions and go through NCERT solutions for Class 8 Maths chapter 9 Algebraic Expressions and Identities, you will find it very easy and one of the strongest parts in Mathematics. You will get NCERT Solutions from Classes 6 to 12 for Science and Maths by clicking on the above link. Here you will get the detailed NCERT Solutions for Class 8 by clicking on the link.

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NCERT Solutions to the Exercises of Chapter 9: Algebraic Expressions and Identities

what are expressions?

Question: 1 Give five examples of expressions containing one variable and five examples of expressions containing two variables.

Answer:

Five examples of expressions containing one variable are:

Five examples of expressions containing two variables are:

Question: 2(i) Show on the number line

Answer:

x on the number line:

Question: 2(ii) Show on the number line :

Answer:

x-4 on the number line:

Question: 2(iii) Show on the number line :

2x+1

Answer:

2x+1 on the number line:


Question: 2(iv) Show on the number line:

Answer:

3x - 2 on the number line

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities Topic 9.2 Terms, Factors and Coefficients

Question:1 Identify the coefficient of each term in the expression.

Answer:

coefficient of each term are given below

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities Topic 9.3 Monomials, Binomials and Polynomials

Question: 1(i) Classify the following polynomials as monomials, binomials, trinomials.

Answer:

Binomial since there are two terms with non zero coefficients.

Question: 1(ii) Classify the following polynomials as monomials, binomials, trinomials.

Answer:

Trinomial since there are three terms with non zero coefficients.

Question:1(iii) Classify the following polynomials as monomials, binomials, trinomials.

Answer:

Trinomial since there are three terms with non zero coefficients.

Question: 1(iv) Classify the following polynomials as monomials, binomials, trinomials.

Answer:

Binomial since there are two terms with non zero coefficients.

Question: 1(v) Classify the following polynomials as monomials, binomials, trinomials.

Answer:

Monomial since there is only one term.

Question: 2(a) Construct 3 binomials with only as a variable;

Answer:

Three binomials with the only x as a variable are:

Question: 2(b) Construct 3 binomials with and as variables;

Answer:

Three binomials with x and y as variables are:

Question: 2(c) Construct 3 monomials with and as variables;

Answer:

Three monomials with x and y as variables are

Question: 2(d) Construct 2 polynomials with 4 or more terms .

Answer:

Two polynomials with 4 or more terms are:

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities Topic 9.4 Like and Unlike Terms

Question:(i) Write two terms which are like

Answer:

Question:(ii) Write two terms which are like

Answer:

we can write more like terms

Question:(iii) Write two terms which are like

Answer:

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities-Exercise: 9.1

Question:1(i) Identify the terms, their coefficients for each of the following expressions.

Answer

following are the terms and coefficient

The terms are and the coefficients are 5 and -3.

Question: 1(ii) Identify the terms, their coefficients for each of the following expressions.

Answer:

the following is the solution

Question:1(iii) Identify the terms, their coefficients for each of the following expressions.

Answer:

Question: 1(iv) Identify the terms, their coefficients for each of the following expressions.

Answer:

The terms are 3, -pq, qr,and -rp and the coefficients are 3, -1, 1 and -1 respectively.

Question:1(v) Identify the terms, their coefficients for each of the following expressions.

Answer:

Above are the terms and coefficients

Question: 1(vi) Identify the terms, their coefficients for each of the following expressions.

Answer:

The terms are 0.3a, -0.6ab and 0.5b and the coefficients are 0.3, -0.6 and 0.5.

Question: 2(a) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Binomial.

Question: 2(b) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Monomial.

Question: 2(c) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

This polynomial does not fit in any of these three categories.

Question: 2(d) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Trinomial.

Question: 2(e) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Binomial.

Question: 2(f) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Trinomial.

Question: 2(g) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Trinomial.

Question: 2(h) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Binomial.

Question: 2(i) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

This polynomial does not fit in any of these three categories.

Question:2(j) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Monomial.

Question: 2(k) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Binomial.

Question: 2(i) Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?

Answer:

Binomial.

Question: 3(i) Add the following.

Answer:

ab-bc+bc-ca+ca-ab=0.

Question:3 (ii) Add the following.

Answer:

Question:3 (iii) Add the following

Answer:

Question: 3(iv) Add the following.

Answer:

Question: 4(a) Subtract from

Answer:

12a-9ab+5b-3-(4a-7ab+3b+12)
=(12-4)a +(-9+7)ab+(5-3)b +(-3-12)
=8a-2ab+2b-15

Question: 4(b) Subtract from

Answer:

Question: 4(c) Subtract from

Answer:

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities Topic 9.7.2 Multiplying Three or More Monomials

Question:1 Find . First find and multiply it by ; or first find and multiply it by .

Answer:

We observe that the result is same in both cases and the result does not depend on the order in which multiplication has been carried out.

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities-Exercise: 9.2

Question: 1(i) Find the product of the following pairs of monomials.

Answer:

Question: 1(ii) Find the product of the following pairs of monomials.

Answer:

Question: 1(iii) Find the product of the following pairs of monomials

Answer:

Question: 1(iv) Find the product of the following pairs of monomials.

Answer:

Question:1(v) Find the product of the following pairs of monomials.

Answer:

Question:2(A) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths respectively.

Answer:

The question can be solved as follows

Question:2(B) Find the areas of rectangles with the following pairs of monomials as their lengths and breadth respectively.

Answer:

the area is calculated as follows

Question:2(C) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths respectively.

Answer:

the following is the solution

Question:2(D) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths respectively.

Answer:

area of rectangles is

Question:2(E) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths respectively.

Answer:

The area is calculated as follows

Question:3 Complete the table of products.


First monomial

Second monomial


...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

Answer:

First monomial

Second monomial

Question:4(i) Obtain the volume of rectangular boxes with the following length, breadth and height respectively.

Answer:

Question:4(ii) Obtain the volume of rectangular boxes with the following length, breadth and height respectively.

Answer:

the volume of rectangular boxes with the following length, breadth and height is

Question:4(iii) Obtain the volume of rectangular boxes with the following length, breadth and height respectively.

Answer:

the volume of rectangular boxes with the following length, breadth and height is

Question:4(iv) Obtain the volume of rectangular boxes with the following length, breadth and height respectively.

Answer:

the volume of rectangular boxes with the following length, breadth and height is

Question:5(i) Obtain the product of

Answer:

the product

Question:5(ii) Obtain the product of

Answer:

the product

Question:5(iii) Obtain the product of

Answer:

the product

Question:5(iv) Obtain the product of

Answer:

the product

Question:5(v) Obtain the product of

Answer:

the product

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities Topic 9.8.1 Multiplying a Monomial by a Binomial

Question:(i) Find the product

Answer:

Using distributive law,

Question:(ii) Find the product

Answer:

Using distributive law,

We have :

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities Topic 9.8.2 Multiplying A Monomial By A Trinomial

Question:1 Find the product:

Answer:

By using distributive law,

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions And Identities-Exercise: 9.3

Question:1(i) Carry out the multiplication of the expressions in each of the following pairs.

Answer:

Multiplication of the given expression gives :

By distributive law,

Question:1(ii) Carry out the multiplication of the expressions in each of the following pairs.

Answer:

We have ab, (a-b).

Using distributive law we get,

Question:1(iii) Carry out the multiplication of the expressions in each of the following pairs.

Answer:

Using distributive law we can obtain multiplication of given expression:

Question:1(iv) Carry out the multiplication of the expressions in each of the following pairs.

Answer:

We will obtain multiplication of given expression by using distributive law :

Question:1(v) Carry out the multiplication of the expressions in each of the following pairs.

Answer:

Using distributive law :

Question:2 Complete the table


First expression

Second expression

Product

(i)

...

(ii)

...

(iii)

...

(iv)

...

(v)

...


Answer:

We will use distributive law to find product in each case.


First expression

Second expression

Product

(i)

(ii)

(iii)

(iv)

(v)


Question:3(i) Find the product.


Answer:

Opening brackets :

or

Question:3(ii) Find the product.

Answer:

We have,

Question:3(iii) Find the product.

Answer:

We have

Question:3(iv) Find the product.

Answer:

We have

or

Question:4(a) Simplify and find its values for

(i)

Answer:

(a) We have

Put x = 3,

We get :


Question:4(a) Simplify and find its values for

(ii)

Answer:

We have

Put

. So We get,

Question:4(b) Simplify and find its value for

(i)

Answer:

We have :

Put a = 0 :

Question:4(b) Simplify and find its value for

(ii)

Answer:

We have

Put a = 1 ,

we get :

Question:4(b) Simplify and find its value for

(iii)

Answer:

We have .

or

Put a = (-1)

Question:5(a) Add: and

Answer:

(a)First we will solve each brackets individually.

; ;

Addind all we get :

Question:5(b) Add: and

Answer:

Firstly, open the brackets:

and

Adding both, we get :

or

Question:5(c) Subtract: from

Answer:

At first we will solve each bracket individually,

and

Subtracting:

or

or

Question:5(d) Subtract: from

Answer:

Solving brackets :

and

Subtracting :

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions And Identities-Exercise: 9.4

Question:1(i) Multiply the binomials.

and

Answer:

We have (2x + 5) and (4x - 3)
(2x + 5) X (4x - 3) = (2x)(4x) + (2x)(-3) + (5)(4x) + (5)(-3)
= 8 - 6x + 20x - 15
= 8 + 14x -15

Question:1(ii) Multiply the binomials.

and

Answer:

We need to multiply (y - 8) and (3y - 4)
(y - 8) X (3y - 4) = (y)(3y) + (y)(-4) + (-8)(3y) + (-8)(-4)
= 3 - 4y - 24y + 32
= 3 - 28y + 32

Question:1(iii) Multiply the binomials

and

Answer:

We need to multiply (2.5l - 0.5m) and (2.5l + 0..5m)
(2.5l - 0.5m) X (2.5l + 0..5m) = using
= 6.25 - 0.25

Question:1(iv) Multiply the binomials.

and

Answer:

(a + 3b) X (x + 5) = (a)(x) + (a)(5) + (3b)(x) + (3b)(5)
= ax + 5a + 3bx + 15b

Question:1(v) Multiply the binomials.

and

Answer:

(2pq + 3q 2 ) X (3pq - 2q 2 ) = (2pq)(3pq) + (2pq)(-2q 2 ) + ( 3q 2 )(3pq) + (3q 2 )(-2q 2 )
= 6p 2 q 2 - 4pq 3 + 9pq 3 - 6q 4
= 6p 2 q 2 +5pq 3 - 6q 4

Question:1(vi) Multiply the binomials.

and

Answer:

Multiplication can be done as follows

X =


=

=

Question:2(i) Find the product.

Answer:

(5 - 2x) X (3 + x) = (5)(3) + (5)(x) +(-2x)(3) + (-2x)(x)
= 15 + 5x - 6x - 2
= 15 - x - 2

Question:2(ii) Find the product.

Answer:

(x + 7y) X (7x - y) = (x)(7x) + (x)(-y) + (7y)(7x) + (7y)(-y)
= 7 - xy + 49xy - 7
= 7 + 48xy - 7

Question:2(iii) Find the product.

Answer:

( + b) X (a + ) = ( )(a) + ( )( ) + (b)(a) + (b)( )
=

Question:2(iv) Find the product.

Answer:

following is the solution

( ) X (2p + q) =

Question:3(i) Simplify.

Answer:

this can be simplified as follows

( -5) X (x + 5) + 25 = ( )(x) + ( )(5) + (-5)(x) + (-5)(5) + 25
=
=

Question:3(ii) Simplify .

Answer:

This can be simplified as

( + 5) X ( + 3) + 5 = ( )( ) + ( )(3) + (5)( ) + (5)(3) + 5
=
=

Question:3(iii) Simplify.

Answer:

simplifications can be

(t + )( - s) = (t)( ) + (t)(-s) + ( )( ) + ( )(-s)
=

Question:3(iv) Simplify.

Answer:

(a + b) X ( c -d) + (a - b) X (c + d) + 2(ac + bd )
= (a)(c) + (a)(-d) + (b)(c) + (b)(-d) + (a)(c) + (a)(d) + (-b)(c) + (-b)(d) + 2(ac + bd )
= ac - ad + bc - bd + ac +ad -bc - bd + 2(ac + bd )
= 2(ac - bd ) + 2(ac +bd )
= 2ac - 2bd + 2ac + 2bd
= 4ac

Question:3(v) Simplify.

Answer:

(x + y) X ( 2x + y) + (x + 2y) X (x - y)
=(x)(2x) + (x)(y) + (y)(2x) + (y)(y) + (x)(x) + (x)(-y) + (2y)(x) + (2y)(-y)
= 2 + xy + 2xy + + - xy + 2xy - 2
=3 + 4xy -

Question:3(vi) Simplify.

Answer:

simplification is done as follows

(x + y) X ( ) = x X ( ) + y ( )
=
=

Question:3(vii) Simplify.

Answer:

(1.5x - 4y) X (1.5x + 4y + 3) - 4.5x + 12y = (1.5x) X (1.5x + 4y + 3) -4y X (1.5x + 4y + 3) - 4.5x + 12y
= 2.25 + 6xy + 4.5x - 6xy - 16 - 12y -4.5x + 12 y
= 2.25 - 16

Question:3(viii) Simplify.

Answer:

(a + b + c) X (a + b - c) = a X (a + b - c) + b X (a + b - c) + c X (a + b - c)
= + ab - ac + ab + -bc + ac + bc -
= + - + 2ab

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions And Identities Topic 9.11 Standard Identities

Question:1(i) Put -b in place of b in identity 1. Do you get identity 2?

Answer:

Identity 1
If we replace b with -b in identity 1
We get,

which is equal to
which is identity 2
So, we get identity 2 by replacing b with -b in identity 1

NCERT Free Solutions for Class 8 Maths Chapter 9 Algebraic Expressions And Identities Topic 9.11 Standard Identities

Question:1 Verify Identity (IV), for .

Answer:

Identity IV
(a + x)(b + x) =
So, it is given that a = 2, b = 3 and x = 5
Lets put these value in identity IV
(2 + 5)(3 + 5) = + (2 + 3)5 +2 X 3
7 X 8 = 25 + 5 X 5 + 6
56 = 25 + 25 + 6
= 56
L.H.S. = R.H.S.
So, by this we can say that identity IV satisfy with given value of a,b and x

Question:2 Consider, the special case of Identity (IV) with a = b, what do you get? Is it related to Identity

Answer:

Identity IV is
If a =b than

(a + x)(a + x) =

Which is identity I

Question:3 Consider, the special case of Identity (IV) with and What do you get? Is it related to Identity ?

Answer:

Identity IV is
If a = b = -c than,
(x - c)(x - c) =

Which is identity II

Question:4 Consider the special case of Identity (IV) with . What do you get? Is it related to Identity?

Answer:

Identity IV is
If b = -a than,

(x + a)(x - a) =
=
Which is identity III

NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions And Identities-Exercise: 9.5

Question:1(i) Use a suitable identity to get each of the following products.

Answer:

(x + 3) X (x +3) =
So, we use identity I for this which is

In this a=x and b = x

=

Question:1(ii) Use a suitable identity to get each of the following products in bracket.

Answer:

(2y + 5) X ( 2y + 5) =
We use identity I for this which is

IN this a = 2y and b = 5

=

Question:1(iii) Use a suitable identity to get each of the following products in bracket.

Answer:

(2a -7) X (2a - 7) =
We use identity II for this which is

in this a = 2a and b = 7

=

Question:1(iv) Use a suitable identity to get each of the following products in bracket.

Answer:


We use identity II for this which is

in this a = 3a and b = -1/2

=

Question:1(v) Use a suitable identity to get each of the following products in bracket.

Answer:


We use identity III for this which is
(a - b)(a + b) =
In this a = 1.1m and b = 4
=
= 1.21 - 16

Question:1(vi) Use a suitable identity to get each of the following products in bracket.

Answer:

take the (-)ve sign common so our question becomes
-
We use identity III for this which is
(a - b)(a + b) =
In this a = and b =

=

Question:1(vii) Use a suitable identity to get each of the following.

Answer:

(6x -7) X (6x - 7) =
We use identity III for this which is
(a - b)(a + b) =
In this a = 6x and b = 7
(6x -7) X (6x - 7) =

Question:1(viii) Use a suitable identity to get each of the following product.

Answer:

take (-)ve sign common from both the brackets So, our question become
(a -c) X (a -c) =
We use identity II for this which is

In this a = a and b = c

Question:1(ix) Use a suitable identity to get each of the following product.

Answer:



We use identity I for this which is

In this a = and b =


=

Question:1(x) Use a suitable identity to get each of the following products.

Answer:




We use identity II for this which is

In this a = 7a and b = 9b

=

Question:2(i) Use the identity to find the following products.

Answer:

We use identity
in this a = 3 and b = 7
=
=

Question:2(ii) Use the identity to find the following products.

Answer:

We use identity
In this a= 5 , b = 1 and x = 4x
=
=

Question:2(iii) Use the identity to find the following products.

Answer:

We use identity
in this x = 4x , a = -5 and b = -1
=
=

Question:1(iv) Use the identity to find the following products.

Answer:

We use identity
In this a = 5 , b = -1 and x = 4x
=
=

Question:2(v) Use the identity to find the following products.

Answer:

We use identity
In this a = 5y , b = 3y and x = 2x
=
=

Question:2(vi) Use the identity to find the following products.

Answer:

We use identity
In this a = 9 , b = 5 and x =
=
=

Question:2(vii) Use the identity to find the following products.

Answer:

We use identity
In this a = -4 , b = -2 and x = xyz
=
=

Question:3(i) Find the following squares by using the identities.

Answer:

We use identity

In this a =b and b = 7

=

Question:3(ii) Find the following squares by using the identities.

Answer:

We use

In this a = xy and b = 3z

=

Question:3(iii) Find the following squares by using the identities.

Answer:

We use

In this a = and b =

=

Question:3(iv) Find the following squares by using the identities.

Answer:

we use the identity

In this a = and b =


=

Question:3(v) Find the following squares by using the identities.

Answer:

we use

In this a = 0.4p and b =0.5q

=

Question:3(vi) Find the following squares by using the identities.

Answer:

we use the identity

In this a = 2xy and b =5y

=

Question:4(i) Simplify:

Answer:

we use

In this a = and b =

=

Question:4(ii) Simplify.

Answer:

we use

In this a = (2x + 5) and b = (2x - 5)

=
= (4x)(10)
=40x

or

remember that

here a= 2x, b= 5

Question:4(iii) Simplify.

Answer:

we use
and
In this a = 7m and b = 8n

=
and

=

So, = +
=

or

remember that

Question: 4(iv) Simplify.

Answer:

we use

1 ) In this a = 4m and b = 5n


=
2 ) in this a = 5m and b = 4n

=

So, = +
=

Question: 4(v) Simplify.

Answer:

we use

1 ) In this a = (2.5p- 1.5q) and b = (1.5p - 2.5q)

=
= 4(p + q ) (p - q)
= 4

Question:4(vi) Simplify.

Answer:

We use identity

In this a = ab and b = bc

=
Now, -
=

Question:4(vii) Simplify.

Answer:

We use identity

In this a = and b =

=
Now, +
=

Question:5(i) Show that

Answer:

L.H.S. =

= R.H.S.

Hence it is prooved

Question:5(ii) Show that

Answer:

L.H.S. = (Using )

= R.H.S.

Question:5(iii) Show that.

Answer:

First we will solve the LHS :

or

= RHS

Question:5(iv) Show that.

Answer:

Opening both brackets we get,

= R.H.S.

Question:5(v) Show that

Answer:

Opening all brackets from the LHS, we get :

= RHS

Question:6(i) Using identities, evaluate.

Answer:

We will use the identity:

So,

Question:6(ii) Using identities, evaluate.

Answer:

Here we will use the identity :

So :

or

Question:6(iii) Using identities, evaluate.

Answer:

Here we will use the identity :

So :

or

Question:6(iv) Using identities, evaluate.

Answer:

Here we will the identity :

or

or

Question:6(v) Using identities, evaluate.

Answer:

Here we will use :

Thus

or

Question:6(vi) Using identities, evaluate.

Answer:

This can be written as :

using

or

Question:6(vii) Using identities, evaluate.

Answer:

This can be written in form of :

or

or

Question:6(viii) Using identities, evaluate.

Answer:

Here we will use the identity :

Thus :

or

or

Question:6(ix) Using identities, evaluate.

Answer:

This can be written as :

or

or

or

Question:7(i) Using , find

Answer:

We know,

Using this formula,

= (51 + 49)(51 - 49)

= (100)(2)

= 200

Question:7(ii) Using , find

Answer:

We know,

Using this formula,

= (1.02 + 0.98)(1.02 - 0.98)
= (2.00)(0.04)

= 0.08

Question:7(iii) Using , find.

Answer:

We know,

Using this formula,

= (153 - 147)(153 +147)

=(6) (300)

= 1800

Question:7(iv) Using , find

Answer:

We know,

Using this formula,

= (1.02 + 0.98)(1.02 - 0.98)

= (2.00)(0.04)

= 0.08

Question:8(i) Using

Answer:

We know,

Using this formula,

= (100 + 3)(100 + 4)

Here x =100, a = 3, b = 4

= 11212

Question:8(ii) Using , find

Answer:

We know,

Using this formula,

= (5 + 0.1)(5 + 0.2)

Here x =5, a = 0.1, b = 0.2

= 26.52

Question:8(iii) Using , find

Answer:

We know,

Using this formula,

= (100 + 3)(100 - 2) = (100 + 3){100 + (-2)}

Here x =100, a = 3, b = -2

= 10094

Question: 8(iv) Using , find

Answer:

We know,

Using this formula,

= (10 - 0.3)(10 - 0.2) = {10 + (-0.3)}{10 + (-0.2)}

Here x =10, a = -0.3, b = -0.2

= 95.

Algebraic Expressions and Identities Class 8 Math Chapter 9-Topics

  • What are Expressions?
  • Terms, Factors and Coefficients
  • Monomials, Binomials,f and Polynomials
  • Like and Unlike Terms
  • Addition and Subtraction of Algebraic Expressions
  • Multiplication of Algebraic Expressions: Introduction
  • Multiplying a Monomial by a Monomial
  • Multiplying two monomials
  • Multiplying three or more monomials
  • Multiplying a Monomial by a Polynomial
  • Multiplying a monomial by a binomial
  • Multiplying a monomial by a trinomial
  • Multiplying a Polynomial by a Polynomial
  • Multiplying a binomial by a binomial
  • Multiplying a binomial by a trinomial
  • What is an Identity?
  • Standard Identities
  • Applying Identities

NCERT Solutions for Class 8 Maths: Chapter-Wise

Chapter -1

Rational Numbers

Chapter -2

Linear Equations in One Variable

Chapter-3

Understanding Quadrilaterals

Chapter-4

Practical Geometry

Chapter-5

Data Handling

Chapter-6

Squares and Square Roots

Chapter-7

Cubes and Cube Roots

Chapter-8

Comparing Quantities

Chapter-9

Algebraic Expressions and Identities

Chapter-10

Visualizing Solid Shapes

Chapter-11

Mensuration

Chapter-12

Exponents and Powers

Chapter-13

Direct and Inverse Proportions

Chapter-14

Factorization

Chapter-15

Introduction to Graphs

Chapter-16

Playing with Numbers

NCERT Solutions for Class 8: Subject-Wise

  • NCERT Solutions for Class 8 Maths
  • NCERT Solutions for Class 8 Science

Some Important Identities From NCERT Book for Class 8 Chapter 9 Algebraic Expressions And Identities

you can write

Can be simplified as follows

Now add each term

You can form the above identities by yourself. These above identities have been used in many problems of NCERT solutions for class 8 maths chapter 9 algebraic expression and identities.

Happy Reading!!!