Final answer:
To determine the tens digit of a 2-digit number that is 12 times its tens digit and has a sum of digits equal to 12, we can set up a system of equations and solve it.
Step-by-step explanation:
To determine the tens digit of a 2-digit number that is 12 times its tens digit and has a sum of digits equal to 12, we can set up a system of equations:
- 10T + U = 12T, where T represents the tens digit and U represents the units digit.
- T + U = 12
To solve this system, we can substitute the second equation into the first equation:
- 10T + (12 - T) = 12T
- 10T + 12 - T = 12T
- 12 + 12 = 12T - 10T + T
- 24 = 3T
- T = 8
Therefore, the tens digit is 8.