Question

How to factor
9y^4-12y^3-12y^2

Answer 1

First factor out the largest common factor of all terms and you have:

3y^2(3y^2-4y-4) now factor quadratic in parentheses...

3y^2(3y^2-6y+2y-4)

3y^2(3y(y-2)+2(y-4))

(3y^2)(3y+2)(y-4)