First you had to add by seven from both sides of equation form.
[tex]-7+\frac{f}{2}+7=-1+7[/tex]
Then simplify by equation.
[tex]\frac{f}{2}=6[/tex]
Next, you multiply by two from both sides of equation form.
[tex]\frac{2f}{2}=6*2[/tex]
And finally, simplify by equation.
[tex]6*2=12[/tex]
[tex]2*6=12[/tex]
[tex]12/6=2[/tex]
[tex]12/2=6[/tex]
[tex]f=12[/tex]
Final answer: [tex]\boxed{f=12}[/tex]
Hope this helps!
And thank you for posting your question at here on brainly, and have a great day.
-Charlie
