Răspuns :
Salut,
(1+2+...+50)/(4+8+...+800)
1+2+...+50 → suma lui Gauss : 50(50+1)/2 = 50•51/2 = 25•51 = 1275.
4+8+...+800 = 4(1+2+...+200) → suma lui Gauss :200(200+1)/2 = 200•201/2 = 100•201 = 20100.
4•20100 = 80400.
(1+2+...+50)/(4+8+...+800) =
=1275/80400 = 51/3216 (am simplificat prin 25).
Succes! :3
(1+2+...+50)/(4+8+...+800)
1+2+...+50 → suma lui Gauss : 50(50+1)/2 = 50•51/2 = 25•51 = 1275.
4+8+...+800 = 4(1+2+...+200) → suma lui Gauss :200(200+1)/2 = 200•201/2 = 100•201 = 20100.
4•20100 = 80400.
(1+2+...+50)/(4+8+...+800) =
=1275/80400 = 51/3216 (am simplificat prin 25).
Succes! :3