Alread answered a few minutes ago.
You can't find two unknowns from one equation, but you can simplify the equation and find one variable in terms of another. Add 2x to both sides of the equation: 6x-2+y=6. Now add 2 to each side: 6x+y=8. If we subtract 6x from each side we get y in terms of x: y=8-6x. For different values of x we can find corresponding values for y; or we can plot a straight line graph which represents the relationship.