a). 924/1092(prin 12) = 77/91(prin 7) = 11/13
b). deoarece sunt inmultiri simplifici numerele scazand puterile:
2 la puterea 7-5
3 la puterea 7-5
7 la puterea 4-2
deci iti raman: (2^2 * 7^2)/3^2 = (4*49)/9= 196/9
c). = 6666/(4444+5555+6666) = 1/9999
d). Sn= n(a1+an)/2
an=a1+(n-1)r
n=524
a1=2
an=2+(524-1)*2=1048
Sn=524(2+1048)/2= (524*1050)/2= 524*525=275100
n=786
a1=3
an=3+(786-1)*3=2358
Sn=786(3+2358)/2=(786*2361)/2=393*2361=927873
275100/927873(prin 3) = 91700/309291
