9x^6+42x^3+49
4x^2-9
(2x-6)·(2x+6)
4x^4+16x^3+16x^2
(4x+4)^2
(2x^2+4x)^2
4x^2-36
(3x^3+7)·(3x^3+7)
x^2-6x+9
(-x+3)^2
(2x+3)·(2x-3)
(3x-5)^2
16x^2+32x+16
9x^2-30x+25
