Question

1+3+5+7+9+...+19
AJUTOR VA ROG !!! :)

Answer 1

$\boxed{1+3+5+...+(2\cdot n-1) = n^2} \rightarrow formula \\ \\ 1+3+5+7+9+...+19 = \\ \\ = 1+3+5+...+(2\cdot 10-1) = 10^2 = 100$