Răspunsuri

2014-10-08T20:35:11+03:00
S=15+16+17+.......+70
S= \frac{56(70+15)}{2} = \frac{56x85}{2} = \frac{4760}{2} = 2380

S=317+318+319+.......+400
S= \frac{84(400+317)}{2} =  \frac{84x717}{2}=42x717=330114

S=1+2+3+.......512
S= \frac{512(512+1)}{2} = \frac{512x513}{2} = \frac{262656}{2} = 131328
bine ca te-ai corectat
Da stiu,nici nu mi-am dat seama de ce prostie am scris
bine ca ai vazut