9(X+Y)的八次方乘以(X-Y)的七次方除以【3(X+Y)³·(X-Y)³】²

问题描述:

9(X+Y)的八次方乘以(X-Y)的七次方除以【3(X+Y)³·(X-Y)³】²

9(X+Y)的八次方乘以(X-Y)的七次方除以【3(X+Y)³·(X-Y)³】²
=9(x+y)^8*(x-y)^7/9*(x+y)^6*(x-y)^6
=(x+y)²(x-y)