Find the measure of each angle. (See Example 3.)
$\angle \mathrm{EFG}$ and $\angle \mathrm{LMN}$ are supplementary angles,
$\mathrm{m} \angle \mathrm{EFG}=(3 \mathrm{x} / 17)^{\circ},$ and $\mathrm{m} \angle \mathrm{LMN}=\left(\frac{1}{2} \mathrm{x}-5\right)^{\circ}$