It's true that (2, 12) is a solution of 3x-1/2 y = 0 .
It's also true that (1, 6), (3, 18), (5, 30), (9, 54), (150, 900),
and (12 million, 72 million) are also perfectly correct solutions.
Any pair of numbers where the 'y' number is six times as much as
the 'x' number is a solution to that equation.
There are an infinite number of them.