The measure of x can be found by solving the equation X + 7 = 3x - 5. This can be done by first subtracting 7 from each side of the equation to get X = 3x - 12. Then, by adding 12 to each side of the equation, we get X + 12 = 3x. Finally, by dividing each side of the equation by 3, we get x = 4. Therefore, the measure of x is 4.