(3a-6b/a+b）-(5a-6b/a-b)-(4a-5b/a+b)-(7a-8b/b-a)

(3a-6b/a+b）-(5a-6b/a-b)-(4a-5b/a+b)-(7a-8b/b-a) (3a-6b)/(a+b) - (5a-6b)/(a-b) - (4a-5b)/(a+b) - (7a-8b)/(a-b a+b>a-b, (a-b)(a b) a/b-b/a 用简便方法计算 （1）(3a-6b/a+b-(5a-6b/a-b)-(4a-5b/a+b)-(7a-8b/b-a) 第二 a-b>a,a+b a+b分之3a-6b－a-b分之5a-6b－a＋b分之4a-5b－b-a分之7a-8b 3a/a-4b +a+b/4b-a -7b/a-4b 计算a+b/b-a-b/b （3a+2b)(6a-5b)(2b-3a)(5a+6b) (a+2b)(2a+4b)(3a+6b)(4a+8b)