通分：(1)y/x(x-y)的平方,x/(y-x)的三次方；（2）a/a的平方-4a+4,b/2a的平方-8a+8,c/3a-6

(1)y/x(x-y)的平方=y(x-y)/x(x-y)³x/(y-x)的三次方=-x²/x(x-y)³（2）a/a的平方-4a+4=a/(a-2)²=6a/6(a-2)²b/2a的平方-8a+8=b/2(a-2)²=3b/6(a-2)²c/3a-6=c/3(a-2)=2c(a-2)/6(a-2)&...