已知2ab分之a+b=3,则a+3ab+b分之3a-7ab+3b=
问题描述:
已知2ab分之a+b=3,则a+3ab+b分之3a-7ab+3b=
答
(a+b)/2ab = 3 a+b = 6ab a+3ab+b分之3a-7ab+3b = [3(a+b) - 7ab]/[(a+b) + 3ab] = (3*6ab - 7ab)/(6ab + 3ab) = 11ab / 9ab = 11/9