Ex 12.1

Chapter 12 Class 8 Factorisation
Serial order wise

### Transcript

Ex 12.1, 2 (Method 1) Factorise the following expressions. (v) 20 𝑙^2 m + 30 a l m20 𝑙^2 m + 30 a l m = (10 × 2) 𝑙^2 m + (10 × 3) alm Taking 10 common, = 10 × (2𝑙^2m + 3 alm) = 10 × ((2l × lm) + (3a × lm)) Taking lm common, = 10 × lm (2l + 3a) = 10lm (2l + 3a) Ex 12.1, 2 (Method 2) Factorise the following expressions. (v) 20 𝑙^2 m + 30 a l m20 𝒍^𝟐 m = 20 × 𝑙^2 × m = 2 × 2 × 5 × 𝑙^2 × m = 2 × 2 × 5 × l × l × m 30 alm = 30 × a × l × m = 2 × 3 × 5 × a × l × m So, 20 𝑙^2m = 2 × 2 × 5 × l × l × m 30 alm = 2 × 3 × 5 × a × l × m So, 2, 5, l and m are the common factors. Now, 20 𝑙^2m + 30 alm = (2 × 2 × 5 × l × l × m) + (2 × 3 × 5 × a × l × m) Taking 2 × 5 × l × m common = 2 × 5 × l × m (2 × l + 3 × a) = 10lm(2l + 3a)

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#### Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.