Question

Calcule a soma dos 8 primeiros termos da P.G. 13,65,...

Answer 1

$> \: resolucao \\ \\ \geqslant \: progressao \: \: geometrica \\ \\ q = \frac{a2}{a1} = \frac{65}{13} = 5 \\ \\ = = = = = = = = = = = = = = \\ \\ > \: a \: soma \: dos \: termos \: da \: pg$

$sn = \frac{a1(q {}^{n} - 1) }{q - 1} \\ sn = \frac{13(5 {}^{8} - 1)}{5 - 1} \\ sn = \frac{13(390625 - 1)}{4} \\ sn = \frac{13 \times 390624}{4} \\ sn = \frac{5078112}{4} \\ sn = 1269528 \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant$

Answer 2

Explicação passo a passo:

Na PG temos

a1 = 13

a2 = 65

q = 65/13 = 5 >>>>

S8 = >??

Sn = a1 * ( q^ n - 1 )/(q - 1)

S8 = 13 * ( 5^8 - 1 )/ ( 5 - 1 )

S8 = 13 * ( 390 625 - 1 ) / 4

S8 =( 13 * 390624)/4

S8 = 5078112/4 = 1269528 >>>>>>>>>