计算;(x-1)[1-(x+1)除以(x-1/x)]

问题描述:

计算;(x-1)[1-(x+1)除以(x-1/x)]

x-1/x不等于0 ==>x不等于0,-1,1
原式=(x-1)[1-(x+1)/(x^2-1)/x]=(x-1)[1-x(x+1)/(x^2-1)]=(x-1)[1-x/(x-1)]=x-1-x=-1