The answer is: `3xy=6` is not a linear equation.
Solving for y we get the function:
`y=2/x` or `y=2x^-1` , x is at the -1 power.
The general form of a linear equation is `ax+b=c`, or expressed as a function `y=ax+b` and the graph is a line. x is at the power of 1
In this case `y=2x` would be a linear equation.
See the graphs below: