👤

calculati : 2+3+4+.....+52 =

Răspuns :

[tex]2+3+4+...+52 = \\ \\ = 1+2+3+4+...+52-1 = \\ \\ = \dfrac{52\cdot (52+1)}{2}-1 = \\ \\ = \dfrac{52\cdot 53}{2}-1 = \\ \\ = 26\cdot 53-1 = \\ \\ = 1378-1 = \\ \\ = 1377[/tex]