Let's begin by listing out the information given to us:
216^(-2n) = (1/6)^(3n+2)
6 is a factor of 216: 216 = 6³
1/6 = 6^(-1)
⇒ 6^(-2*3n) = 6^[(-1*(3n+2)]
⇒ 6^(-6n) = 6^(-3n-2)
Since both sides are in the same base, we equate the exponents. We have:
-6n = -3n - 2
Add "6n" from both sides, we have:
-6n + 6n = -3n + 6n - 2 ⇒ 0 = 3n - 2
⇒ 3n = 2
