Question

S= 1:(1×4)+1:(4×7)+1:(7×10)×1:(10×13)+.........+1:(301×304)
In locul semnelor de impartire trebuia sa fie ceva de genu (1 supra 1×4).
Multumesc anticipat.

Answer 1

1/3(1/1-1/4) +1/3(1/4-1/7) + 1/3(1/7-1/10)+..........+1/3(1/301-1/304) =1/3[1-1/4+1/4-1/7+1/7-1/10+..........+1/301-1/304] =1/3(1-1/304) = 1/3 ·303/304 =101/304