Question

Is `x/y = 1/2` a direct variation equation?

Answer 1

Since `x/y = 1/2` and assuming `y!=0`
the equation can be re-arranged as
`y = 2x`
which would be a direct variation equation
except for the restriction that `y` and therefore `x` can not be equal to `0`.

Check your local definition of "direct variation equation" (there is some variation) to determine if this is considered an acceptable restriction.