Answer:
x³ -6x² +x +20
Step-by-step explanation:
The distributive property is useful for making sure you have all of the partial products.
(x^2–x–4)(x–5) = x(x^2–x–4) -5(x^2–x–4)
= (x^3 -x^2 -4x) +(-5x^2 +5x +20)
= x^3 +(-1-5)x^2 +(-4+5)x +20
= x^3 -6x^2 +x +20