if the two angles are Alternate Interior Angles. then:
[tex]\begin{gathered} m\angle F=m\angle H \\ \text{Where:} \\ m\angle F=6x+7 \\ m\angle H=9x-14 \\ 6x+7=9x-14 \\ \text{Solving for x:} \\ 7+14=9x-6x \\ 21=3x \\ \frac{21}{3}=x \\ 7=x \\ x=7 \end{gathered}[/tex]So:
[tex]m\angle F=6x+7=6(7)+7=42+7=49[/tex]