The equation is 2(3 + x) = 14.

2(3) + 2(x) = 14                  (Apply Distributive property: a(b + c) = ab + ac)

6 + 2x = 14                         (Multiply: )

Apply subtraction property of equality: Subtract 6 from each side.

             (Apply Commutative property of addition: a + b = b + a)

                         (Apply additive inverse property: )

                                 (Subtract: )

                            (Divide each side by 2)

                                 (Cancel common terms)

                                   (Divide: )

Check:

To check, substitute x = 4 in 2(3 + x) = 14.

2(3 + 4) = 14

2(7) = 14                            (Add: 3 + 4 = 7)

14 = 14                              (Multiply: )

The solution is .