Question

定义计算a*b=b/a-a+b,请计算：（x+1）*（x-1）

Answer 1

（x+1）*（x-1）=(x-1)/(x+1) -(x+1)+(x-1)

=(x-1)/(x+1)-x-1+x-1

=(x-1)/(x+1) -2