Question

Factor the polynomial by grouping.

1. -20 + 5y^2 + 4z - y^2z

Answer 1

rearrange things just a bit and you have

5y^2-20 - y^2z + 4z
5(y^2-4) - z(y^2-4)
(5-z)(y^2-4)
(5-z)(y+2)(y-2)