4x2 - 9y Not factorable from what I see.
The GCF is 4x2.
4x2-y2 = (2x-y)(2x+y)
If that's + 4x2, the answer is 2x(x2 + 2x - 4)
4x2+20x+25 (2x+5)^2
4x2-36x+81 (2x-9)(2x-9)
4x2 - 23xy + 15y2 = (4x - 3y)(x - 5y)
4x
16 - a2
It is: 4x2-7x-15 when factored is (4x+5)(x-3)
Take out the common factor, which in this case is 4x2. Divide each of the terms by this common factor. 12x2 - 4x3 = 4x2(3+x)
4x2-4x-120 = (2x+10)(2x-12) when factored