Question

alguem pode me ajudar nessa PG​

Answer 1

$a_7=2187=3^7\\ a_1=3$

$\boxed{a_n=a_kq^{n-k}}$

$a_7=a_1q^6\ \therefore\ 3^7=3q^6\ \therefore$

$q^6=3^6\ \therefore\ q=\pm\sqrt[6]{3^6}\ \therefore$

$\boxed{q=\pm3}$