Expand the following:
(x-4) (x+3) (x-5)

(x-4) (x-5) = (x) (x) + (x) (-5) + (-4) (x) + (-4) (-5) = x^2-5 x-4 x+20 = x^2-9 x+20:
x^2-9 x+20 (x+3)

 | | x^2 | - | 9 x | + | 20
 | | | | x | + | 3
 | | 3 x^2 | - | 27 x | + | 60
x^3 | - | 9 x^2 | + | 20 x | + | 0
x^3 | - | 6 x^2 | - | 7 x | + | 60:
Answer: |x^3 - 6x^2 - 7x + 60