2012PP-I-02

19-06-2023 app.cch 尚無留言

答案：

a = \frac{2 b - 5}{3 b}

\begin{array}{rcl} \frac{5 + b}{1 - a} & = & 3 b \\ 5 + b & = & 3 b - 3 a b \\ 3 a b & = & 2 b - 5 \\ a & = & \frac{2 b - 5}{2 b} \end{array}