I would say that the unfinished puzzle has more than one piece and the missing piece is only one, itself.
Answer:
x = 11
Step-by-step explanation:
Raising both sides to the fifth power, we get:
27(x - 2) = 3⁵
x - 2 = 3⁵ / 27
x - 2 = 3⁵ / 3³
x - 2 = 3⁽⁵⁻³⁾ = 3² = 9
x = 11
72 is multiples of 3,9, and 12