Question

factorise x^3-x^2-17x-15.

The answer should come (x+1) (x-5) (x+3).

Please do step by step

Answer 1

Answer:

Step-by-step explanation:

the sum of the coefficient is 0 when x = 1.

so (x-1) is a solution

x^{3}-x^{2} -17x-15

(x-1) (x^{2} +2x -15)

(x-1) ( x^{2} -3x + 5x -15)

(x-1) (x+5) (x-3) = 0

so the solution is x=1 , x= -5 , x=3