Question

Factorise : 2(x + 2y)² - 5(x + 2y) + 2

Answer 1

2(x + 2y)² - 5(x + 2y) + 2

Let x + 2y = a, then

2a² - 5a + 2

⇒ 2a² - a - 4a + 2

= a(2a - 1) - 2(2a - 1)

= (2a - 1)(a - 2)

= {2(x + 2y - 1)} {(x + 2y) - 2}   ...(a = x + 2y)

= (2x + 4y - 2)(x + 2y - 2)