we know that
Directly proportional is a relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other
so
[tex]y=kx[/tex]
in this problem
for
[tex]x=8[/tex]
[tex]y=14 \\ 14=8k [/tex]
divide by 8 both sides
[tex]k=14/8 \\ k=7/4[/tex]
find the value of y for [tex]x=12[/tex]
[tex]y=(7/4)12 \\ y=21[/tex]
the answer is
[tex]y=21[/tex]
