Question

f(x)= 2x + 1
f(1)+f(2)+.............+f(50) =?

Answer 1

Stiind ca f(x)= 2x +1 =>

f(1)= 2 ×1 +1
f(2)= 2 ×2 +1
.....
f(50)=2×50 +1

=> S = 2(1+2+...+50)+1×50
S=2× (50 ×51) pe doi +50 (se duce 2 cu 2)

=> 50 ×51 + 50 = 2600

Sper ca te-am ajutat :)

Answer 2

f(1)+f(2)+.............+f(50) =
2*1 + 1+
2*2 + 1+
2*3 + 1+
.............
2*50 + 1 =
---------------------
2(1+2+3+...+50) + 1*50 = 2*50*51:2  +  50 = 50*51 + 50 = 50(51+1) = 50*52 = 2600