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 - 8x² + (24 - 8 - 12)x + 48
= x³ - 8x² + 4x + 48