问题
解答题
计算：（x-1-y-1）÷（x-2-y-2）-xy（x+y）-1．
答案
原式=（
-1 x
）÷（1 y
-1 x2
）-1 y2 xy x+y
=
÷y-x xy
-(y-x)(y+x) x2y2 xy x+y
=
×y-x xy
-x2y2 (y-x)(y+x) xy x+y
=
-xy y+x xy x+y
=0．
搜题请搜索小程序“爱下问搜题”
计算：（x-1-y-1）÷（x-2-y-2）-xy（x+y）-1．
原式=（
-1 x
）÷（1 y
-1 x2
）-1 y2 xy x+y
=
÷y-x xy
-(y-x)(y+x) x2y2 xy x+y
=
×y-x xy
-x2y2 (y-x)(y+x) xy x+y
=
-xy y+x xy x+y
=0．