Question

calcular el valor de:Q=2+4+6+8+....40​

Answer 1

Respuesta:

$sn = \frac{n(a1 + an)}{2} \\ q = \frac{20(2 + 40)}{2} \\ q = \frac{20(42)}{2} \\ q = \frac{840}{2} \\ q = 420$