The equations are

               Equation (1)

                       Equation (2)

Since the coefficients of the b-terms are additive inverses, you can eliminate these terms by adding the equations. Add the equations to eliminate variable b.

Write the equations in column form and add the corresponding columns. \ \ \ \

                     (Divide each side by 3)

                            (Cancel common terms)

Now Substitute –1 for a in either equation to find the value of b.

                (Equation 1)

         (Replace a by –1)

               (Multiply: )                 

   (Add 2 on each side)

   (Commutative property: )

               (Additive inverse property: )

                       (Add: )

                  (Divide each side by negative 3)

                          (Cancel common terms)

                                (Divide: )

The solution is .

The solution is .