Soal kombinasi kelas 12tentukan nilai n jika :n+1 C 5 = n C 4

(n+1)!/5!(n+1-5)! = n!/4!(n-4)!
(n+1)(n)(n-1)(n-2)(n-3)(n-4)! / 5!(n-4)! = (n)(n-1)(n-2)(n-3)(n-4)! / 4!(n-4)!
(n+1) / 5! = 1 / 4!
(n+1) / 5×4! = 1 / 4!
(n+1) / 5 = 1
(n+1) = 5
n = 5 – 1
n = 4