Question

先化简x加1分之1减x的平方减1分之1除以x的平方减2x加1分之x加1

然后带自己喜欢的值进去

Answer 1

1楼最后算错了 引用一下：
1/(x+1) - 1/(x²-1) ÷ (x+1)/(x²-2x+1)
=1/(x+1) - 1/(x+1)(x-1) × (x-1)(x-1)/(x+1)
=1/(x+1) - (x-1)/(x+1)²
=[ (x+1)-(x-1) ] /(x+1)²
=2/(x+1)²

Answer 2

你这个可以说是神题了，完全没有括号，你看看对不对吧，
1/(x+1) - 1/(x²-1) ÷ (x+1)/(x²-2x+1)
=1/(x+1) - 1/(x+1)(x-1) × (x-1)(x-1)/(x+1)
=1/(x+1) - (x-1)/(x+1)²
=[ (x+1)-(x-1) ] /(x+1)²
=0