Solving Equations using Elimination Method:

The equations are

                                Equation (1)

                                   Equation (2)

Since the coefficients of the a-terms are same, you can eliminate

these terms by adding the equations. Subtract the equations to eliminate

variable a.

Write the equations in column form and subtract the corresponding columns.

Apply division property of equality: if a = b then 

                  (Divide each side by negative 6)

                               (Cancel commen terms)

                                    (Divide: )

Now substitute 3 for b in either equation to find the value of a.

                         (Equation 1)

                 (Substitute )

                     (Multiply: )

     (Subtract 15 from each side)

               (Apply additive inverse proparty: )

                     (Apply  additive identity proparty: )

                             (Subtract: )

                         (Divide each side by 13)

                                           (Cancel commen terms)

                                     (Divide: )

The solution is ,

The solution is  .