The equations are \ \

                                     Equation (1)

                                         Equation (2)

\

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

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

                               (Divide each side by 4)

                                               (Cancel commmen terms)

                                        (Divide: )

Now Substitute 5 for m in either equation to find the value of n.

                                (Equation 2)

                                 (Replace m = 5)

Apply subtraction proparty of equality: If a = b then

                     (Subtrtact 5 from each side)

                          (Commutative proparty:   )

                                            (Additive inverse property: )

                                       (Subtract: )

Apply division property of equality: If a = b then

                                  (Divide each side by –2)

                                         (Cancel commen terms)

The solution is

The solution is .