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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.

.

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Now Substitute –5 for r in either equation to find the value of s.

                           (Equation 1)

                    (Replace r by –5)

                        (Multiply: )

       (Add 15 to each side)

       (Commutative property: )

                       (Additive inverse property: )

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                               (Add: )

                          (Divide each side by negative 5)

                                  (Cancel common etrms) \ \

                                          (Divide: )

The solution is .

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The solution is .