2x÷(x-y)^3+(2y+x)÷(y-x)^3-(3y-2x)÷(y-x)^3

问题描述:

2x÷(x-y)^3+(2y+x)÷(y-x)^3-(3y-2x)÷(y-x)^3

原式=2x*1/(x-y)^3-(x+2y)*1/(x-y)^3+(2x-3y)*1/(x-y)^3
=(2x-x-2y+2x-3y)/(x-y)^3
=(3x-5y)/(x-y)^3