You have the following equation:
[tex]\frac{-10x+14}{b}=f[/tex]In order to solve the previous equation for x, you proceed as follow:
[tex]\begin{gathered} \frac{-10x+14}{b}=f \\ -10x+14=fb \\ -10x=fb-14 \\ x=\frac{fb-14}{-4} \\ x=-\frac{1}{4}fb+\frac{14}{4} \\ x=-\frac{1}{4}fb+\frac{7}{2} \end{gathered}[/tex]when you have used on each step:
- multiply by b both sides
- subtract 14 both sides
- divide by -4 both sides
- simplify
Hence, the solution for x is:
[tex]x=-\frac{1}{4}fb+\frac{7}{2}[/tex]