x-y/x+y×x+y/y-x要过程,结果等于-1,是怎么算的

问题描述:

x-y/x+y×x+y/y-x要过程,结果等于-1,是怎么算的

x-y/x+y×x+y/y-x
=(x-y)*(x+y)/-(x-y)*(x+y)
=(x^2-y^2)/-(x^2-y^2)
=-1