Question

Determine o termo a6 em cada PG:

a) (-7,14,-28,...)
b) (-48,-24,-12,...)
c) (64/25,8/5,1,...)

Answer 1

a) (-7,14,-28,...)
b) (-48,-24,-12,...)
c) (64/25,8/5,1,...)

$a) \\ a_6=a_1.q^5\\ \\ a_6=(-7).(-2)^5\\ \\ a_6=(-7).(-32)\\ \\ \boxed{a_6=224}$

$b) \\ a_6=a_1.q^5\\ \\ a_6=(-48).(\frac{1}{2})^5\\ \\ \boxed{a_6=(-48).\frac{1}{32}=-\frac{48}{32}=-\frac{3}{2}}$

$c)\\ a_6=a_1.q^5\\ \\ \boxed{a_6=(\frac{64}{25}).(\frac{5}{8})^5=(\frac{64}{25}).(\frac{3125}{32768})=\frac{125}{512}}$