Question

一道化简求值！！！！~~~

[（x-y)／（x+y）]²÷[（y-x）／（x²＋2xy＋y²）]²▪[1／（x＋y）],其中x=-4，y=1.

Answer 1

=[(x-y)²/(x+y)²]×[(x+y)^4/(x-y)²]*1/(x+y)
=(x+y)²/(x+y)
=x+y
=-4+1
=-3

Answer 2

[（x-y)／（x+y）]²÷[（y-x）／（x²＋2xy＋y²）]²▪[1／（x＋y）]=[（x-y)／（x+y）]²÷[（x-y）²／(x+y)^4]·1/(x+y)=）]=[（x-y)／（x+y）]²▪[(x+y)²／-（x-y）]²·1/(x+y)约分得=(x+y)=带入x=-4，y=1得-3