Mike thought of a number. He added to it to two other numbers. One of these numbers was 12 less than his number, the other was 12 more than his number. The result of the addition was 15. What was Mike's original number?

If Mikes original number is x, the equation is?

The number is?

number 1 + number 2 + number 3 = 15

Number 1 = x + 12

Number 2 = x - 12

Number 3 = x

(x + 12) + (x - 12) + x = 15

x + 12 + x - 12 + x = 15

x + x + x + 12 - 12 = 15

3x = 15

x = 15/3 = 5

Check:

Number 1 = 17

Number 2 = 5 - 12 = - 7

Number = 5

number 1 + number 2 + number 3 = 15

17 + (-7) + 5 = 15

10 + 5 = 15

15 = 15

Answer is 5