Elimination Method:

The equations are

              Equation (1)

               Equation (2)

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

by subtracting the equations. Subtract the equations to eliminate variable s.

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

.

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

          (Equation 2)

                          (Multiply: )

         (Add 10 to each side)

         (Apply commutative property of addition: )

                       (Apply additive inverse property: )

                          (Apply additive identity property: )

                                  (Add: )

                             (Divide each side by negative 5)

                                        (Cancel common terms)

                                             (Divide: )

The solution is .