Question

先化简,再求值:2a+1/(a²-1)×a²-2a+1/(a²-a)-1/a+1,其中a=-1/2

各位帮帮忙，拜托了！快一点啊

Answer 1

2a+1/(a²-1)×a²-2a+1/(a²-a)-1/a+1,其中a=-1/2
=2a+1/(a+1)(a-1)×(a-1)²/a(a-1)-1/a+1
=2a+1/a(a+1)-1/a+1
=(2a+1-a)/a(a+1)
=(a+1)/a(a+1)
=1/a
=1/(-1/2)
=-2