Question

Se da f(x)=3x+6 si imi cere S=f(1) +f(2) +...+f(35)

Answer 1

f(1)=3*1+6

f(2)=3*2+6

...................

f(35)=3*35+6

S=f(1)+f(2)+......+f(35)=3*1+6+3*2+6+.........+3*35+6=3(1+2+...+35)+6*35=3*35*36/2+210=1890+210=2100