NCERT Class 8 Mathematics Chapter 9 Algebraic Expressions and Identities CBSE Board Sample Problems (For CBSE, ICSE, IAS, NET, NRA 2022)

Get unlimited access to the best preparation resource for CBSE/Class-8 : get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-8.

Algebraic Expressions and Identities

Algebraic Expressions is the expression having constants and variable. It can have multiple variable and multiple power of the variable

Example

Some Important Points on Algebraic Expressions

 Terms Description Terms factors Terms are added to form expressions terms themselves can be formed as the product of factors Coefficient The numerical factor of a term is called its numerical coefficient or simply coefficient Monomial Algebraic expression having one terms is called monomialsExample3x Binomial Algebraic expression having two terms is called BinomialExample Trinomial Algebraic expression having three terms is called TrinomialExample Polynomial An expression containing, one or more terms with non-zero coefficient (with variables having non negative exponents) is called a polynomial Like terms When the variable part of the terms is same, they are called like terms Unlike terms When the variable part of the terms is not same, they are called like terms

Operation on Algebraic Expressions

 S. no Operation Descriptions 1. Addition We write each expression to be added in separate row, while doing so we write like terms one below the otherOrWe add the expression together on the same line and arrange the like term togetherAdd the like termsWrite the Final algebraic expression 2. Subtraction We write each expression to be subtracted in a separate row, while doing so we write like terms one below the other and then we change the sign of the expression which is to be subtracted i.e.. . + becomes-and-becomes + or We subtract the expression together on the same line, change the sign of all the term which is to be subtracted and then arrange the like term togetherAdd the like termsWrite the Final algebraic expression 3. Multiplication We have to use distributive law and distribute each term of the first polynomial to every term of the second polynomial.When you multiply two terms together you must multiply the coefficient (numbers) and add the exponentsAlso as we already know ++ equals = , +-or -+ equals- and-- equals +Group like terms

What is an identity?

An identity is an equality, which is true for all values of the variables in the equality.

Developed by: