Verified answer

Resposta:

Explicação passo a passo:

primeiro termo =x

razão= 3

soma = 160

montando temos.

x +xr+xr²+xr³ =160

x( 1+r+r²+r³= 160

x(1+1+3+9+27)=160

40x= 160

x= 160/40

x= 4

[tex] > \: resolucao \\ \\ \geqslant \: progressao \: \: geometrica \\ \\ sn = \frac{a1(q {}^{n} - 1) }{q - 1} \\ \\ 160 = \frac{a1(3 {}^{4} - 1) }{3 - 1} \\ \\ 160 = \frac{a1(81 - 1)}{2} \\ \\ 160 = \frac{a1(80)}{2} \\ \\ 320 = 80a1 \\ \\ a1 = \frac{320}{80} \\ \\ a1 = 4 \\ \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant [/tex]