Question

Factorise : x^3 + 13x^2 + 32x +
20​

Answer 1

Answer:

(x + 1)(x + 2)(x + 10)

Step-by-step explanation:

f(x) = x³ + 13x² + 32x + 20

f(- 1) = (- 1)³ + 13(- 1)² + 32(- 1) + 20 = 0 ⇒ (x + 1) is a factor of f(x)

(x³ + 13x² + 32x + 20) ÷ (x + 1) = x² + 12x + 20

x² + 12x + 20 = (x + 2)(x + 10)

x³ + 13x² + 32x + 20 = (x + 1)(x + 2)(x + 10)