Angles F and C are supplementary, then their addition is equal to 180 degrees, that is,
[tex]m\angle F+m\angle C=180[/tex]
Substituting with data and solving for x:
[tex]\begin{gathered} (157-17x)+108=180 \\ (157+108)-17x=180 \\ 265-17x=180 \\ 265-17x-265=180-265 \\ -17x=-85 \\ \frac{-17x}{-17}=\frac{-85}{-17} \\ x=5 \end{gathered}[/tex]
