Question

计算①a²-b²／a²+2ab+b²÷2a-2b／a+b②a-1／a÷a-1／a

Answer 1

①(a²-b²／a²+2ab+b²)÷(2a-2b／a+b)

=[(a+b)(a-b)/(a+b)²]÷[2(a-b)/(a+b)]

=[(a-b)/(a+b)]÷[2(a-b)/(a+b)]

=1/2

②(a-1／a)÷(a-1／a²)

=(a-1／a)*(a²/a-1)

=a

②[(a-1)／a]÷[(a-1)／a]²

=[(a-1)／a]*[a/(a-1)]²

=a/(a-1)

=1-1/(a-1)