Question

Is `3x-6y=0` a direct variation?

Answer 1

Yes. Every time `x` increases of one unit `y` increases of a fixed amount equal to `1/2`.
If you separate `y` on one side and `x` on the other you'll find:
`6y=3x`
and:
`y=3/6x`
or
`y=1/2x`