Question

Tolong dibantu no 101 secepatnya

Answer 1

8P2 = 2n^2 + n + 1
8!/(8 - 2)! = 2n^2 + n + 1
(8.7.6!)/6! = 2n^2 + n + 1
56 = 2n^2 + n + 1
0 = 2n^2 + n - 55
(2n + 11)(n - 5) = 0
n = -11/2 atau n = 5
Kita pilih n = 5 karena dalam kombinasi atau permutasi n harus bilangan asli
2nCn = 10C5 = 10!/(10-5)!.5! = (10.9.8.7.6.5!)/(5!.5.4.3.2.1)
= (10.9.8.7.6)/(5.4.6)
= 2 . 9 . 2 . 7
= 252