Question

Determine a soma dos seis primeiros termos da PG(3,12,48,....).

Answer 1

,

$> resolucao \\ \\ \geqslant progressao \: \: geometrica \\ \\ q = \frac{a2}{a1} \\ q = \frac{12}{3} \\ q = 4 \\ \\ \\ sn = \frac{a1(q {}^{n} - 1) }{q - 1} \\ \\ sn = \frac{3(4 {}^{6} - 1) }{4 - 1} \\ \\ sn = \frac{3(4096 - 1)}{3} \\ \\ sn = \frac{3 \times 4095}{3} \\ \\ sn = 4095 \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant$