2(x-2y)²-7(x-2y)³+3(2y-x)²+(2y-x)³
4个回答

2(x-2y)²-7(x-2y)³+3(2y-x)²-(2y-x)³

=2(x-2y)²-7(x-2y)³+3(x-2y)²+(x-2y)³← 平方可以换位置不管符号,立方则正常考虑符号.

=5(x-2y)²-6(x-2y)³←合并同类项

=(x-2y)²(5-6x+12y)←提取公因式((x-2y)²)