Question

Factorise the polynomial x^3 - 5x^2 +2x +8, (x-4) is a factor.

Pllsss i need help ASAP! T^T

Answer 1

x^3 - 5x^2 + 2x + 8

= (x^3 - 4x^2) - (x^2 - 4x) - (2x - 8)

= x^2(x - 4) - x(x - 4) - 2(x - 4)

= (x^2 - x - 2)(x - 4)

= [x(x - 2) + (x - 2)](x - 4)

= (x - 2)(x + 1)(x - 4)

Hope this helps!

:)