Question

Find the zeroes of x3+5x2-9x-45

Answer 1

Let P(x) = x^3 + 5x^2- 9x - 45 =

=x^2(x + 5) - 9 (x+5)

= (x+5) (x^2- 9)

= (x+5) (x+3) (x-3)