Question

先化简[（a²-b²）/(a²-ab)]÷[a+(2ab+b²）/a],当b=-

Answer 1

[（a²-b²）/(a²-ab)]÷[a+(2ab+b²）/a]

=[(a+b)(a-b)/[a(a-b)]]÷[a+b(2a+b)/a]

=[(a+b)/a]×[a/(a+2ab+b^2)]

=(a+b)/[a+2ab+b^2]

当b=-1时,选择a=0

那么原式=（0-1）/(0+0+1)

=-1