Question

calcule n sabendo que : (n+n)!/(n-1)!/72

Answer 1

2n !/(n-1)!/72

2n(2n-1)(2n-2)/(n-1)!!/72

2n.(2n-1).2.(n-1)/(n-1)!/72
 
4n(2n-1)/72

n(2n-1)/18=(2n²-n)/18