Question

Calcule a soma dos dez primeiros termos da pg - 3 - 6

Answer 1

$> \: resolucao \\ \\ \geqslant \: progressao \: \: geometrica \\ \\ a1 = - 3 \\ a2 = - 6 \\ n = 10 \\ q = \frac{a2}{a1} = \frac{ - 6}{ - 3} = 2 \\ \\ = = = = = = = = = = = = =$

$sn = \frac{a1(q {}^{n} - 1)}{q - 1} \\ sn = \frac{ - 3(2 {}^{10} - 1)}{2 - 1} \\ sn = \frac{ - 3(1024 - 1)}{1} \\ sn = \frac{ - 3 \times 1023}{1} \\ sn = - 3069 \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant$