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 - 12x² + (24 + 8 + 12)x - 48
= x³ - 12x² + 44x - 48