Answers

  • Brainly User
2015-10-30T07:53:14+08:00
Let the third number be x

Equation:
10 + 12 + x = 15
         3

10 + 12 + x = 15 (3)

10 + 12 + x = 45
22 + x = 45
x = 45 - 22
x = 23    The third number is 23.

To check:

10 + 12 + x = 15
        3

10 + 12 + 23 = 15
         3

45 = 15
 3

15 = 15
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