Question

Va rog ajutati ma 2+4+6+8+...+98+100=

Answer 1

S = 2 + 4 + .. +  100

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

aplicam Gauss

= 2×50×51 : 2

= 50×51

= 2550

Answer 2

2+4+6+8+....+98+100

Aplicăm suma lui Gauss

Suma noastră are doar termeni pari deci numarul de termeni este 50

S=[(2+100)×50]/2=(102×50)/2=5100/2=2550