Question

(1²+2)+(2²+2)+(3²+2)+...+(12²+2)

Answer 1

Hola (｡•̀ᴗ-)✧

Respuesta:

$674$

Explicación paso a paso:

${= (1^2 + 2 ) + (2^2 +2) + (3^2 + 2) +...+ (12^2 + 2)}$

$\boxed{= \sum_{n=1}^{12} (n^2+2)}$

$= \frac{ 12(12+1) \bigl ( 2(12)+1 \bigr )}{6} + 2(12)$

$= 2(13) \bigl ( 25 \bigr )+ 24$

$= 650 + 24$

$= 674$