FACTORISATION : FACTORISATION CBSE
CLASS 8
Factors of natural numbers : Factors of natural numbers Any natural number is written as a product of other natural nos.
e.g. 30 = 5x6 =3x10 =2x15
Factors of algebraic expressions : Factors of algebraic expressions Terms are formed as product of factors
5ab = 5 x a x b
In expression 3a(a+2) = 3 x a x (a+2) the factors are irreducible.
What is factorisation? : What is factorisation? When we factorise an algebraic expression, we write it as a product of factors.
These factors may be numbers , algebraic variables or algebraic expressions.
Factorisation by regrouping terms : Factorisation by regrouping terms Rearranging the terms with common terms.
Factorisation using identities : Factorisation using identities Observe the expression.
If it has a form that fits the right hand side of one of the identities , then the expression corresponding to the left hand side of the identity gives the desired factorisation.
(a+b)2 = a2+2ab+b2
(a-b)2 = a2 -2ab+b2
(a2-b2) = (a+b)(a-b)
Factors of the form (x+a)(x+b) : Factors of the form (x+a)(x+b) In general , for factorising an algebraic expression of the type x2+px+q , we find two factors a and b of q (i.e. the constant term) such that
ab = q
a+b = p
Division of algebraic expressions : Division of algebraic expressions Polynomial divided by monomial
Polynomial divided by polynomial
Thank you ! : Thank you !