(x+2)+x(2+x)
=(x+2)+x(x+2)
=(x+2)(x+1)
(4x-3)²-4(x+1)²
=(4x-3)²-[2(x+1)]²
=[(4x-3)+2(x+1)][(4x-3)-2(x+1)]
=(4x-3+2x+2)(4x-3-2x-2)
=(6x-1)(x-5)
(2a-b)²+8ab
=4a²-4ab+b²+8ab
=4a²+4ab+b²
=(2a+b)²
2ab²-4abc
=2ab(b-2c)
多项式2ab²-4abc的公因式是2ab