12(x-2y)²-17(x-2y)³+13(2y-x)²-10(2y-x)³

问题描述:

12(x-2y)²-17(x-2y)³+13(2y-x)²-10(2y-x)³

=12(x-2y)²+13(x-2y)²-17(x-2y)³+10(x-2y)³
=25(x-2y)²-7(x-2y)³
=-18(x-2y)