Answer:
V = 3.
Explanation:
(I'll try.)
v/9 = 4/12
you cancel the common factor which is four.
next, you multiple both sides by nine, which make:
9v
_ = 1 , 9
_____
9 3
,,
and I guess you simplify it, and then it becomes V = 3.
I suck at explaining, so you'll just have to trust me by word.