Question

factorise: (x - 2y)² - 12(x - 2y) + 32 

Answer 1

(x - 2y)² - 12(x - 2y) + 32 

Let (x - 2y) = a

∴ (x - 2y)² = a²

∴ (x - 2y)² - 12(x - 2y) + 32

= a² - 12a + 32

= a² - 8a - 4a + 32

= a(a - 8) - 4 (a - 8)

= (a - 8)(a - 4)

= (x - 2y - 8)(x - 2y - 4)
(Substituting the value of a)