The equations are

                     Equation (1)

                  Equation (2)

Eliminate the variable n by adding the equation (1) and (2).

         (Add the corresponding columns)

Apply division property of equality: if a = b, then.

                 (Divide each side by 8)

                      (Cancel common terms)

                           (Divide: )

Substitute in equation (1).

Apply subtraction property of equality; if a = b, then .

        (Subtract 2 from each side)

Apply commutative property of addition: .

              (Apply Additive inverse property: )

                (Apply Additive identity property: )

                     (Subtract: )

Apply multiplication property of equality; if a = b, then .

          (Multiply each side by negative one)

                    (Product of two same signs is posivite)

                        (Product of twodifferent signs is negative)

The solution is .

The solution is .