Ex 12.3

Chapter 12 Class 8 Factorisation
Serial order wise

### Transcript

Ex 12.3, 5 Factorise the expressions and divide them as directed. (iii) (5๐^2 โ 25p + 20) รท (p โ 1)We first factorise ใ๐๐ใ^๐ โ 25p + 20 Taking 5 common, = 5 (๐^2โ5๐+4) By middle term splitting, = 5 (๐^2โ๐โ๐๐+4) = 5 [(๐^2โ p) โ (4p โ 4)] = 5 [p(p โ 1) โ 4 (p โ 1)] Taking (p โ 1) common, = 5 (p โ 1)(p โ 4) Splitting the middle term We need to find two numbers whose Sum = โ5 Product = 4 So, we write โ5p = โp โ 4p Dividing (ใ5๐ใ^2โ25๐+20)รท(๐+1) = (ใ5๐ใ^2 โ 25๐ + 20)/((๐ โ1)) = (๐ (๐ โ๐) (๐โ๐))/((๐ โ๐)) = 5 ร ((๐ โ 1) )/((๐ โ 1)) ร (p โ 4) = 5 (p โ 4)

#### 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.