Question

Nilai n yang memenuhi persamaan:
(n+2)!-6n.(n-1)!=0

Answer 1

(n+2) ! - 6n (n-1)! =0

(n+2)! = 6n (n-1)!

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

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

(n+2)(n+1)(n) = 6n

(n+2)(n+1) = 6

n^2 + n +2n +2 = 6

n^2 +3n +2 = 6

n^2 +3n +2-6 = 0

n^2 +3n -4 = 0

(n+4) (n-1) = 0

n = -4 atau n = 1

nilai n harus positif maka n = 1