So,
We'll solve it with only one placeholder, since that's simpler.
Jim's age = J
Carla's age = C
Tommy's age = T
J = base
Carla's age = J + 5
Tommy's age = Carla's age + 6 or J + 5 + 6 or J + 11
Sum of ages = 31
(J) + (J + 5) + (J + 11) = 31
3J + 16 = 31
Subtract 16 from both sides
3J = 15
Divide both sides by 3
J = 5
Carla's age = J + 5
Carla's age = 10
Tommy's age = Carla's age + 6
Tommy's age = 10 + 6 or 16
5 + 10 + 16 = 31
15 + 16 = 31
31 = 31 This checks.
Jim is 5.
Carla is 10.
Tommy is 16.
