((243)^(n/5) × 3^(2n+1)) / (9^n × 3^(n−1)) = ?

Explanation

Since 243 = 3^5, (243)^(n/5) = 3^n.
The expression becomes:
(3^n × 3^(2n+1)) / (3^(2n) × 3^(n-1))
= 3^((3n+1) - (3n-1))
= 3^2 = 9.