(1) b/(a-b) + a/(a+b)-2ab/(b^2-a^2)

问题描述:

(1) b/(a-b) + a/(a+b)-2ab/(b^2-a^2)
(2) [1-1/(1-X) ] ÷X/X-1

1, (a+b)/(a-b)
2,1