Question

obtenha o primeiro termo da pg em que a 7=31250 e q = 5

Answer 1

$a_7=a_1\cdot{q}^6\\\\a_1=\dfrac{a_7}{q^6}\\\\\\a_1=\dfrac{31250}{5^6}\\\\\\a_1=\dfrac{2\cdot5^6}{5^6}\\\\\\\boxed{a_1=2}$