Question

Sa se determine nr natural n, $n \geq5$ stiind ca

$\frac{(n-3)!}{(n-5)!} = 6$

Answer 1

simplifici prin (n-5)! si obtii
(n-3) (n-4)=6
n^2-7n+12-6=0
n^2-7n+6=0
delta=49-24=25
n1=7+5/2=6
n2=7-5/2=1, n=6, deoarece n=>5..