Prelucrezi ecuatia
8*(n+1)!/5!*(n+1-5)!=3*n*(n-1)*(n-2)
8*(n+1)!/5!*(n-4)!=3n*(n-1)*(n-2)
8*(n-4)!*(n-3)*(n-2)(n-1)*n/5!*(n-4)!=3n*(n-1)*(n-2)
8(n-3)(n-2)*(n-1)*n/5!=3n(n-1)(n-2)
Imparti egalitatea prin (n-2)*(n-1)*n
8(n-3)/5!=3
8(n-3)=3*5!
8(n-3)=3*120 Imparti egalitatea pri 8
n-3=3*15
n-3=45
n=3+45
n=48
