Question

caucula n sabendo que
a) n! =30
(n-2)! ​

Answer 1

n!

------- = 30

(n-2)!

n(n-1)(n-2)!

--------------- = 30

(n-2)!

n(n-1)=30

n²-n-30=0

∆= 1+120= 121 => √∆=11

n= -b+√∆/2a = 1+11/2= 12/2= 6 ✓