先化简，再求值：(1+1x-1)÷xx2-1，请你选一个你喜欢的x值代入计算．

Question

先化简，再求值： (1+(1)/(x-1) )÷(x)/(x2 -1) ，请你选一个你喜欢的x值代入计算．

Answer 1

原式=（ (x-1)/(x-1) + (1)/(x-1) ）× ((x-1)(x+1))/(x)
= (x)/(x-1) × ((x-1)(x+1))/(x)
=x+1．
当x=2时，原式=2+1=3．