The equations are

 Since the coefficients of the x-terms,+3 and -3,are additive inverses,

you can eliminate these terms by adding the equations. .

add the equations to eliminate variable x.

             (Write the equations in column form and add)

                           (Divide each side by 6)

                                (Cancel common terms)

                                     (Divide: )

Now Substitute 6 for y  in either equation to find the value of x.

   (Equation 1)

                (Subtract 12 from each side)

                     (Additive inverse property: )

                           (Additive indentity property: )

                                 (Add:  )

                            (Divide each side by 3)

                                (Cancel common terms)

                                  (Divide: )

The solution is .

The solution is .