Factorisation using common factors

Chapter 12 Class 8 Factorisation
Concept wise

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Ex 12.1, 2 (Method 1) Factorise the following expressions. (vii) 10 π^2 β 15 π^2 + 20 π^2 Now, 10π^2= 10 Γ π^2 = 2 Γ 5 Γ π^2 = 2 Γ 5 Γ a Γ a 15π^2 = 15 Γ π^2 = 3 Γ 5 Γ π^2 = 2 Γ 5 Γ b Γ b 20π^2 = 20 Γ π^2 = 2 Γ 2 Γ 5 Γ π^2 = 2 Γ 2 Γ 5 Γ c Γ c So, 5 is the common factor. 10π^2 β 15π^2 + 20π^2 = (2 Γ 5 Γ a Γ a) β (3 Γ 5 Γ b Γ b) + (2 Γ 2 Γ 5 Γ c Γ c) Taking 5 common = 5 Γ ((2 Γ a Γ a) β (3 Γ b Γ b) + (2 Γ 2 Γ c Γ c)) = 5 Γ (2π^2 β 3π^2 + 4π^2) = 5 (2π^π β 3π^π + 4π^π) Ex 12.1, 2 (Method 2) Factorise the following expressions. (vii) 10 π^2 β 15 π^2 + 20 π^2 10 π^2 β 15 π^2 + 20 π^2 = (5 Γ 2) π^2 β (5 Γ 3 ) π^2 + (5 Γ 4) π^2 Taking 5 common, = 5 (2π^π β 3π^π + 4π^π)