Question

Fie functia f : R⇒R cu f(x)=2x+3
Calculati: S= f(1)+f(2)+f(3)+......+f(100)

Answer 1

S= 2*1+3+2*2+3+....+2*100+3

S=2*(1+2+....+100) + 3*100

S=2*$\frac{100*101}{2}$ + 300

S=100*101 +300

S=10100 + 300

S=10400