Rewrite the equation as 3x+9=y.
Subtract 9 from both sides of the equation.
Divide each term by 3 and simplify.
Divide each term in 3x=y-9 by 3.
Cancel the common factor of 3.
Cancel the common factor.
Divide x by 1.
Divide -9 by 3.
Solve for x y=3x+9