\[
\begin{array}{rcl}
\frac{AO}{DO} & = \frac{AF}{BF} + \frac{AE}{CE} \\
\frac{BO}{EO} & = \frac{BD}{CD}+\frac{BF}{AF} \\
\frac{CO}{OF} & = \frac{CD}{DB}+\frac{CE}{AE} \\
\end{array}
\]