6(x-y)3次方+15(y-x)的平方-9(y-x)的3次方

问题描述:

6(x-y)3次方+15(y-x)的平方-9(y-x)的3次方

原式=6(x-y)³+15(x-y)²+9(x-y)³
=15(x-y)³+15(x-y)²
=15(x-y)²(x-y+1)