Question

Solve the following equation by factorization:

x² + 18x = 40

Answer 1

Given,

⇒ x² + 18x = 40

⇒ x² + 18x – 40 = 0

⇒ x² + 20x – 2x – 40 = 0

⇒ x(x + 20) – 2(x + 20) = 0

⇒ (x – 2)(x + 20) = 0

⇒ x – 2 = 0 or x + 20 = 0   ...[Using zero-product rule]

⇒ x = 2 or x = –20

Hence, x = {–20, 2}.