Question

Aflati suma numerelor impare cuprinse intre 1 si 1001

Answer 1

de la 1 la 1001 sunt 501 numere impare.
-notez suma respectiva cu S$S=1+2+3+...+501 \\ S= \frac{501(501+1)}{2} \\ S= \frac{501\cdot502}{2} \\ S=501\cdot251 \\ S=125751$

Answer 2

S=1+2+3+...+501
S=501+502:2
S=501·251
S=125751