.化简什么的(x-y+4xy/x-y)(x+y-4xy/x+y)抱歉我只是懒得算了..T T

(x-y+4xy/x-y)(x+y-4xy/x+y)=[(x-y)^2+4xy/x-y][(x+y)^2-4xy/x+y]=[(x+y)/x-y)][(x-y)^2/x+y]=(x+y)(x-y)
符号不太好打 这样能不能看得懂？

1-8X^2Y^2/(X^2-Y^2)

(x-y+4xy/x-y)(x+y-4xy/x+y)
=[(x-y)^2+4xy][(x+y)^2-4xy]/[(x-y)(x+y)]
=[(x+y)^2(x-y)^2]/[(x-y)(x+y)]
=(x-y)(x+y)
=x^2-y^2

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