2+4+6+8+10+...........+98+100
Inmultim fiecare numar cu 2
2x2+2x4+2x6+2x8+2x10+.........+2x98+2x100
Dam factor comun pe 2 si rezolvam ca o suma a lui gauss normala
2x(2+4+6+8+10+........+98+100)
2x [(2+100)x100]:2
102x100:1=10200
Sper ca te-am ajutat :)
Ce nu intelegi intreaba :)
2+4+6+8+10+...+98+100=
=2(1+2+3+....+50)=
=2×(50×51)/2=
=50×51=2550
