Answer:
15
Step-by-step explanation:
((x-3)^2) / 6 = x + 9
Multiply both sides by 6.
6x + 54 = ((x-3)^2)
Expand.
6x + 54 = x^2 - 6x + 9
Simplify.
x^2 - 12x - 45 = 0
Solve using quadratic formula.
x = 15, -3
Since ages can only be positive, the answer is 15 years old.
