(1)
2(x+Y)的平方-(y+x)的立方
=2(x+y)²-(y+x)³
=(x+y)²(2-x-y)
(2)
4x(x-y)的平方+12(y-x)的平方
=4x(x-y)²+12(y-x)²
=4(x-y)²(x+3)