What is 9y2 - 25yz - 6z2?

9y2-25yz-6z2

Multiply first and last terms

9*-6=-54

Find factors of -54

2,-27 = 2+-27=-25

-2,27 = -2+27=25

Rewrite

9y2-27zy+2zy-6z2

Factor pairs of terms

9y2-27zy = 9y(y-3z)

2zy-6z2= 2z(y-3z)

9y2-27zy+2zy-6z2= 9y(y-3z)+2z(y-3z)

Factor:

9y(y-3z)+2z(y-3z) = (y-3z)(9y+2z)