Hi I need help solving:
The sum \(\[6\left( 1\cdot3 + 2\cdot4 + \dots + n(n+2) \right)\]\) is equal to a polynomial \(f(n)\) for all \(n \ge 1.\) Write \(f(n)\) as a polynomial with terms in descending order of n.
Thank you!!
The answer is f(n) = 4n^3 + 5n^2 + 9n.
+28 
