This trinomial is in a special form that can be
factored into the product of two binomials.
So we set up two sets of parenthses.
As the first term, we have the factors of x², x and x.
For the second term, we have the factors of -40 that add to -3.
In this case, these factors are -8 and +5.
So our answer is (x - 8)(x + 5).
