Question

Na P.G. (x, 4, 4x, ...), calcule x e o valor numérico do sexto termo da P.G.

Answer 1

$\dfrac{a_2}{a_1}=\dfrac{a_3}{a_2}\\\\\\\dfrac{4}{x}=\dfrac{4x}{4}\\\\\\4x^2=4\times4\\4x^2=16\\x=\pm2\\\\\\\{2,4,8...\\\\\\\\a_6=a_1\times q^5\\a_6=2 \times 2^5\\a_6=2\times 32\\a_6=64$