Răspunsuri

2014-10-14T19:56:48+03:00
 \frac{(n-2)(n-1)n!} {(n-2)!} = \frac{10n(n-1)!}{(n-1)!} [/tex]
se simplifica n-2 si n-1, iar apoi ajungi la o ecuatie (n-1)n-10n
o egalezi cu 0 si rezolvi ecualtia de gradu 2
Cel mai inteligent răspuns!
2014-10-14T19:59:54+03:00
N(n-1)=10n(n-2)
n²-n=10n²-20
n²-10n²-n=-20
-9n²-n=-20
9n²+n=20
1 5 1