(2x-y)^7(y-2x)^5(y-2x)^4

问题描述:

(2x-y)^7(y-2x)^5(y-2x)^4

(2x-y)^7(y-2x)^5(y-2x)^4
=(2x-y)^7[-(2x-y)^5](2x-y)^4
=-(2x-y)^(7+5+4)
=-(2x-y)^16