Question

计算求1+（a-1÷1-a）÷（1+a÷a²-2a+1）的计算过程及结果

Answer 1

原式=1 + [(a-1)/-(a-1)] / [(1+a) / (a-1)^2]

=1 - [(a-1)/(a-1)] / [(1+a) / (a-1)^2]

=1 - [(a-1)^2 / (1+a)]

=[(1+a)/(1+a)] - [(a-1)^2 / (1+a)]

=[(1+a) - (a-1)^2] / (1+a)

=(-a^2 + 3a)/(1+a)