Solve the system of equation using Substitution Method:

The equations are

                           Equation (1)

                               Equation (2)

Solve the equation (1) for y.

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

          (Subtract 4x from each side)

Apply commutative property of addition: .

                       (Apply Additive inverse property: )

         (Multiply each side by negative one)

                             (Product of two same signs is positive)

Substitute    in Equation (2).

Distribute terms using distributive property: .

                       (Simplify)

                              (Add: )

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

        (Subtract 40 from each side)

                        (Apply Additive inverse property: )

                             (Subtract: )

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

                        (Divide each side by 9)

                            (Cancel common terms) \ \

                                  (Divide: )

Substitute in equation .

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

            (Add 1 to each side)

                       (Add: 13 + 3 = 16)

                                   (Apply additive inverse property: )

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

                            (Divide each side by 2)

                                  (Cancel common terms) \ \

                                      (Divide: )

The solution is.