Question

How do you factor `x^3 + 7x^2 + 15x + 9`?

Answer 1

`f(x) = (x + 1)(x + 3)^2`

Explanation:

Because (a - b + c - d) = 0, then f(-1) = 0. One factor is (x + 1).
After division -->
`f(x) = (x + 1)(x^2 + 6x + 9) =`
`f(x) = (x + 1)(x + 3)^2`