[tex]A_{ADB}=A_{AOB}+A_{AOD}\\
A_{ACB}=A_{AOB}+A_{BOC}zz
A_{ADB}=A_{ACB}=144=>\\
A_{AOD}=A_{BOC}=x\\
A_{ADB}=144=x+ \frac{OM\cdot 24}{2} \\
A_{ADC}=108=x+ \frac{ON \cdot 18}{2} \\
x+12OM=144=>OM= \frac{144-x}{12} \\
x+9ON=108=>ON= \frac{108-x}{9} \\
OM+ON=12\\
\frac{144-x}{12} + \frac{108-x}{9}=12\\
x= \frac{432}{7} [/tex]
Obs.OM este inatimea din O in triunghiul AOB iar ON este inaltimea din O in triunghiul DOC.