Question

Factorise :-x^3-23x^2+142x+120

Answer 1

Answer:

x

3

−23x

2

+142x−120

=x

3

−x

2

−22x

2

+22x+120x−120

=x

2

(x−1)−22x(x−1)+120(x−1)

=(x−1)(x

2

−22x+120)

=(x−1)[x

2

−10x−12x+120]

=(x−1)[x(x−10)−12(x−10)]

=(x−1)(x−10)(x−12)