I'm a bit confused about way to write this equation down, so I will solve this both ways, and you will chose whitch you had in mind ;)
[tex]\frac{v+9}{3}=8[/tex]
[tex]v+9=8*3[/tex]
[tex]v=24-9[/tex]
[tex]v=15[/tex]
or:
[tex]v+\frac{9}{3}=8[/tex]
[tex]v+3=8[/tex]
[tex]v=8-3[/tex]
[tex]v=5[/tex]