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

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

The topic is introduced to study about the application of algebraic terms or application of variables in various kinds of scenarios. NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities will give you a detailed analysis and solution for every single question covered in the NCERT and also it makes your task easy while solving the problems.

Algebra is the most important branch of mathematics. In which we learn the application of variable and how equation forms and split using different kinds of techniques.In NCERT Class 8 Maths Chapter 9 Algebraic Expressions and Identities we will learn about finding coefficient of the variable in equation, product of the equation, division of the equation, subtraction of the equation and creating quadratic equation by the product of its two roots.  Most of the students don't feel better while dealing with algebraic part of mathematics but if you go through some basics and practise lots of questions related to the concept then the algebra would become your one of the strongest parts in mathematics. It requires much attention then that of other mathematical sub topics.

## Topics of NCERT for Class 8 Maths Chapter 9 - Algebraic Expressions and identities:-

9.1 What are Expressions?

9.2 Terms, Factors and Coefficients

9.3 Monomials, Binomials and Polynomials

9.4 Like and Unlike Terms

9.5 Addition and Subtraction of Algebraic Expressions

9.6 Multiplication of Algebraic Expressions: Introduction

9.7 Multiplying a Monomial by a Monomial

9.7.1 Multiplying two monomials

9.7.2 Multiplying three or more monomials

9.8 Multiplying a Monomial by a Polynomial

9.8.1 Multiplying a monomial by a binomial

9.8.2 Multiplying a monomial by a trinomial

9.9Multiplying a Polynomial by a Polynomial

9.9.1 Multiplying a binomial by a binomial

9.9.2 Multiplying a binomial by a trinomial

9.10 What is an Identity?

9.11 Standard Identities

9.12 Applying Identities

Few important identities explained in the NCERT class 8 chapter 9 Algebraic Expressions and identities are listed below.

1. $(a+b)^2=(a^2+2ab+b^2)$

we can write

$(a+b)^2=(a+b)(a+b)$

This is simplified as follows

$(a+b)(a+b)=a\times a+a\times b+a\times b+b\times b$

$a\times a+a\times b+a\times b+b\times b=a^2+ab+ab+b^2$

$=a^2+2ab+b^2$

This is how we obtained the identity

$(a+b)^2=(a^2+2ab+b^2)$

Important identities explained in the NCERT class 8 chapter 9 Algebraic Expressions and identities

2. $(a-b)^2=(a^2-2ab+b^2)$

3. $(a-b)(a+b)=a^2-b^2$

Try to find out how the above identities are formed by yourself.

Where we will use this identity? To understand these let's see an example

Example: What is the value of $105\times105$ ?

Solution: Instead of multiplying it directly we will now use identity

$105\times105=(100+5)(100+5)=(100+5)^2$ this is of the form $(a+b)^2$

we know that $(a+b)^2=(a^2+2ab+b^2)$

here a=100, b =5 so,

$(100+5)^2=(100^2+2\times100\times5+5^2)=10000+1000+25=11025$

This is how we will use identities to solve problems as mentioned above

## NCERT Solutions For Class 8 Maths: Chapter-wise

 Chapter -1 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-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