Question

qual é o 5° termo da PG (-120, -60, -30,...)

Answer 1

$PG (-120, -60, -30,...)\\\\ a_{1} =-120\\q= \frac{1}{2}\\ n=5\\ a_{n} = a_{5} = ? \\\\\\ a_{n} = a_{1} * q^{n-1} \\\\ \\ a_{5} =-120 * \frac{1}{2}^{5-1}\to\\\\ a_{5} =-120 * \frac{1}{2}^{4}\to\\\\ a_{5} =-120 * \frac{1}{16}\to \\\\a_{5} =\frac{-120}{16}\to\\\\ a_{5} =\frac{-15}{2}$