Question

分式加减混合计算(a/a-1-a²/a²-1)÷(1-1/a+1)

Answer 1

=[a(a+1)-a²]/(a+1)(a-1)÷(a+1-1)/(a+1)

=a/(a+1)(a-1)×(a+1)/a

=1/(a-1)