a=21/4+3/2+9/2*1/2 /10/3:8/3:3/2
a=21/4+3/2+9/4 / 10/3*3/8*2/3
a=21/4+6/4+9/4 / 5*1/2*1/3
a=36/4 / 5*1/2*1/3
a= 9/ 5/6
a=54/5
b= [2/5*(1/7+4/7*1/5)+3/35] * 14
b=[2/5*(1/7+4/35)+3/35] * 14
b=(2/5*9/35+3/35)*14
b=(18/175+3/35)*14
b=33/175 * 14
b=33/25*2
b=66/25
Numarul de ani = 50*54/5-25*66/25
Numarul de ani = 10*54-66
Numarul de ani = 540-66
Numarul de ani = 474
