Question

Tolongggggggggggggggg a dan b

Answer 1

(a)
n! / (n-2)! = 6
(n-1)(n-2)! / (n-2)! = 6
(n-1) = 6
n = 6 + 1
n = 7

(b)
(n+2)! / n! = 42
(n+2)(n+1)(n!) / n! = 42
(n+2)(n+1) = 42
n^2 + 2n + n +2 = 42
n^2 + 3n + 2 - 42 = 0
n^2 + 3n - 40 = 0
(n+8)(n-5) = 0
maka
n = -8 atau n= 5