Question

72= (n+1)! / ((n+1)-2)!
what is the answer to this?

Answer 1

72 = (n + 1)! / (n - 1)!

= (n + 1)(n)(n - 1)! / (n - 1)!

72 = n² + n

n² + n - 72 = 0

(n + 9)(n - 8) = 0

n = -9 will not work, so n = 8.