We have the expression:
[tex]\frac{F}{-4}-1=-3[/tex]
Adding 1 on both sides, we get:
[tex]\begin{gathered} \frac{F}{-4}-1+1=-3+1 \\ \frac{F}{-4}=-2 \end{gathered}[/tex]
Multiplying by -4 on both sides:
[tex]\begin{gathered} \frac{F}{-4}(-4)=-2(-4) \\ F=8 \end{gathered}[/tex]
