3a方*(x-y)的立方-4b方*(y-x)平方等于?

问题描述:

3a方*(x-y)的立方-4b方*(y-x)平方等于?

=3a²(x-y)³-4b²(x-y)²
=(x-y)²(3a²x-3a²y-4b²)