Question

Factorise the following.​

Answer 1

iii. (l + m - n)(l - m + n)

vi. (5a -b) ( 5b - a)

Explanation:

iii. l² - (m - n)²

= (l + m - n)(l - m + n)

vi. 4(a+b)² - 9(a-b)²

= (2(a+b))² - (3(a-b))²

= (2(a+b) + 3(a-b)) (2(a+b) - 3(a-b))

= (2a+2b + 3a - 3b) (2a+2b - 3a + 3b)

= (5a -b) ( 5b - a)

Answer 2

Q. 1) l²- (m - n)²

=(l - m + n)(l + m - n)

Q.2) 4(a+b)²- 9(a-b)²

= [(2(a+b))²- (3(a-b))²]

=[2(a+b)+3(a-b)][ 2(a+b)-3(a-b)]

=[2a+2b+3a-3b][2a+2b-3a+3b]

=[5a-b][5b-a] ]