Elimination Method:

The equations are

             Equation (1)

           Equation (2)

Since the coefficients of the s-terms are additive inverses, you can eliminate

these terms by adding the equations. Add the equations to eliminate variable t.

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

Apply division property of equality: if a = b then 

                    (Divide each side by 12)

                                (Cancel common terms)

Now, find the b value by substituting in either equation.

                  (Equation 1)

                         (Multiply: )

             (Subtract 6 from each side)

             (Apply commutative property of addition: )

                   (Apply additive inverse property: )

                         (Apply additive identity property: )

                           (Subtract: )

                     (Divide each side by 5)

                            (Cancel common terms)

The solution is .