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

You have already studied what algebraic expressions are and the role of variables and constants in forming algebraic expressions. In NCERT Solutions for Class 8 Maths, Chapter 9, you’ll study in detail about various types of algebraic expressions, like and unlike terms, how to perform various mathematical calculations on algebraic expressions such as addition, subtraction and multiplication. You’ll also learn what identities are and how they are useful in algebraic expressions. Algebraic expressions have several real-life applications – while purchasing grocery, filling-in the petrol tank, finding consecutive numbers, finding the cost per person or dimensions of a rectangle. Knowingly or unknowingly, everywhere algebraic expressions are used.

Let’s take a look at topics and sub-topics of 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

9.8 Multiplying a Monomial by a Polynomial

9.9 Multiplying a Polynomial by a Polynomial

9.10 What is an Identity?

9.11 Standard Identities

9.12 Applying Identities

 In Class 8 Maths Chapter 9, one will learn –

Section 9.2 – In this section, you’ll learn some useful concepts like terms, expressions, the product of factors, coefficient, numerical coefficient and more.

Section 9.3 – In this section, you’ll study about monomials, binomials, trinomials and polynomials.

Section 9.4 – In this section, you will acquire knowledge about what like and unlike terms are in algebraic expressions. Remember, only like terms can be added or subtracted.

Section 9.5 – In this section, you will learn to perform addition or subtraction of algebraic expression. You need to observe that addition or subtraction is done by writing the like terms one below the other.

Section 9.6 – In this section, you’ll learn how to multiply algebraic expressions. Multiplication of algebraic expression is very useful in real-life situations such as finding the area of a rectangle or calculating the interest to be paid or calculating speed and time.

Section 9.7 – In this section, you’ll study the technique of multiplying monomial by a monomial using the rules of exponents and powers.

Section 9.8 – In this section, you’ll learn how to multiply a monomial by a polynomial (either by a binomial or a trinomial).

Section 9.9 – In this section, you‘ll learn the techniques of multiplying a polynomial by a polynomial through various examples given.

Section 9.10 – In this section, study what an identity is and its role in solving algebraic expressions. Algebraic identities are also helpful in factorising polynomials.

Section 9.11 – In this section, you will learn three standard identities, which are extremely useful in real-life applications. These identities are acquired by multiplying a binomial by another binomial.

Section 9.12 – In this section, you’ll get in-depth knowledge about how to solve several binomial expressions in a simple way using identities.

In this chapter, you are provided with several examples along with their solutions for a clear understanding of Algebraic Expressions and Identities. To know more about Class 8 Maths Chapter 9 Algebraic Expressions and Identities, you should explore the exercises below. You can also download the Algebraic Expressions and Identities Class 8 NCERT Solutions PDF, solved by expert Maths trainers.