你好!
lim(x→1) [ 2/(x² -1) - 1/(x-1) ]
= lim(x→1) [2 - (x+1)] / [(x+1)(x-1)]
= lim(x→1) (1 - x) / [(x+1)(x-1)]
= lim(x→1) - 1 / (x+1)
= - 1/2