Question

化简求值括号a减b分之一减a加b分之一除以a方减2ab加b方分之b

Answer 1

[1/(a-b)-1/(a+b)]÷[b/(a²-2ab+b²)]
=[2b/(a+b)(a-b)]·[(a-b)²/b]
=2(a-b)/(a+b).
以相应的a和b值代入上式即可。