化简 3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)²

问题描述:

化简 3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)²
3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)²
(X-Y)视为整体

3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)²
=(3-6)(X-Y)²+(-4+7)(X-Y)
=-3(X-Y)²+3(X-Y)