设这个分数为:b/a.
又题意得:(b/a + b/a) + (b/a - b/a) + (b/a)/(b/a) = 2*b/a + 0 + 1
= 2*b/a + 1
= 4/3
经过计算,得:b/a=1/6
你自己演算下