Question

ajutatima ca nu inteleg cum sa rezolv 1+2+3...+10

Answer 1

1+2+3+...+10=
$\frac{10*11}{2}=5*11=55$

Answer 2

$\displaystyle 1+2+3+...+10= \frac{10(10+1)}{2} = \frac{10 \times 11}{2} = \frac{110}{2} =55$