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Ex 12.1, 2 (vii) - Chapter 12 Class 8 Factorisation

Last updated at May 29, 2023 by

Ex 14.1, 2 (vii) - Factorise 10 a^2 - 15 b^2 + 20 c^2 - Teachoo

Ex 14.1, 2 (vii) - Chapter 14 Class 8 Factorisation - Part 2
Ex 14.1, 2 (vii) - Chapter 14 Class 8 Factorisation - Part 3

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Ex 12.1, 2 (Method 1) Factorise the following expressions. (vii) 10 π‘Ž^2 – 15 𝑏^2 + 20 𝑐^2 Now, 10π‘Ž^2= 10 Γ— π‘Ž^2 = 2 Γ— 5 Γ— π‘Ž^2 = 2 Γ— 5 Γ— a Γ— a 15𝑏^2 = 15 Γ— 𝑏^2 = 3 Γ— 5 Γ— 𝑏^2 = 2 Γ— 5 Γ— b Γ— b 20𝑐^2 = 20 Γ— 𝑐^2 = 2 Γ— 2 Γ— 5 Γ— 𝑐^2 = 2 Γ— 2 Γ— 5 Γ— c Γ— c So, 5 is the common factor. 10π‘Ž^2 – 15𝑏^2 + 20𝑐^2 = (2 Γ— 5 Γ— a Γ— a) βˆ’ (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) βˆ’ (3 Γ— b Γ— b) + (2 Γ— 2 Γ— c Γ— c)) = 5 Γ— (2π‘Ž^2 βˆ’ 3𝑏^2 + 4𝑐^2) = 5 (2𝒂^𝟐 βˆ’ 3𝒃^𝟐 + 4𝒄^𝟐) Ex 12.1, 2 (Method 2) Factorise the following expressions. (vii) 10 π‘Ž^2 – 15 𝑏^2 + 20 𝑐^2 10 π‘Ž^2 – 15 𝑏^2 + 20 𝑐^2 = (5 Γ— 2) π‘Ž^2 βˆ’ (5 Γ— 3 ) 𝑏^2 + (5 Γ— 4) 𝑐^2 Taking 5 common, = 5 (2𝒂^𝟐 βˆ’ 3𝒃^𝟐 + 4𝒄^𝟐)

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