Question

Encontre o nono termo da P.G. (4, 16, 64,.)

Answer 1

a₁ = 4
a₂ = 16
a₃ = 64
n = 9
q = 16 / 4 = 4
         a₇ = a₁ * q^n-1
         a₇ = 4 * 4⁹⁻¹
         a₇ = 4 * 4⁸
         a₇ = 4 * 65536
         a₇ = 262144

Espero ter ajudado. Valeu!

Answer 2

$P.G. (4, 16, 64,.)\\\\\\ a_n=a_9=?\\a_1=4\\ n=9\\ q=4\\\\\\ a_n=a_1*q^{n-1}\\\\\\ a_9=4*4^{9-1}\to \\\\ a_9=4*4^{8}\to \\\\ a_9=4*65.536\to \\\\ a_9=262.144$