Question

factorise ^3 − 3^2 − 9 − 5

Answer 1

Answer:

Substitute 5 for x in x3 – 3x2 – 9x – 5

53 – 3(5)2 – 9(5) – 5 = 125 - 75 - 45 - 5 = 0

So, 5 is zero of the expression x3 – 3x2 – 9x – 5

This means (x - 5) is a factor of x3 – 3x2 – 9x – 5

Divide x3 – 3x2 – 9x – 5 by x - 5

Factorization of x3 – 3x2 – 9x – 5