Question

Factorise: 4x2 9y2

Answer 1

4x2 9y2 = 22x2 32y2= (2x)2 (3y)2

Substituting a = 2x and b = 3y in

(a2 b2) = (a + b)(a b), we have

(2x)2 (3y)2 = (2x + 3y)(2x 3y)

Factors of 4x2 9y2are (2x + 3y) and (2x 3y)