Question

Ajutoooooor, dau coroana si puncte !!! E urgent! Plss ajutor

Answer 1

Se observa ca la numarator avem o progresie aritmetica cu a1=2 si ratie r=3.
Aflam cati termeni are progresia, adica aflam al catalea termen este 362
an = a1+(n-1)r = 2 + (n-1)*3 = 362
2 + 3n-3 = 362
3n-1 = 362
3n = 363
n = 121
Progresia are 121 termeni. Calculam suma primilor 121 termeni:
Sn = (a1+an)*r/2
S121 = (a1+a121)*n/2 = (2+362)*121/2 = 364*121/2 = 182*121

La numitor avem o progresia aritmetica cu a1 = 3 si ratie r=4. Calculam cati termeni are progresia:
an = a1+(n-1)r = 3+(n-1)*4 = 483
3+4n-4 = 483
4n-1 = 483
4n = 484
n = 484:4
n = 121
Calculam suma primilor 121 termeni: 
S121=(a1+a121)*n/2 = (3+483)*121/2 = 486*121/2 = 243*121

Fractia se tranforma in :
182*121/243*121 = 182/243 fractie ireductibila