Question

Simplify: (x + 6) (x − 4) (x − 2)

Answer 1

Using identity:
(x + a)(x + b)(x + c) = x³ + (a + b + c)x² + (ab + bc + ca)x + abc

(x + 6)(x − 4)(x − 2)
= x³ + (6 − 4 − 2)x² + [6 × (−4) + (−4) × (−2) + (−2) × 6]x + 6 × (−4) × (−2)
= x³ − 0x² + (−24 + 8 − 12)x + 48
= x³ − 28x + 48