Question

Qual o sétimo termo da PG ( 1, -2,...)?

Answer 1

$PG~ ( 1, -2,...)\\\\\\ a_1=1\\\\ q= \frac{-2}{1} =-2\\\\ n=7\\\\ a_7=?\\\\\\ a_n=a_1 \times q^{n-1}\\\\\\ a_7=1\times (-2)^{7-1}\to\\\\ a_7=1\times (-2)^6\to\\\\ a_7=1\times 64\to\\\\ \large\boxed{a_7=64}\\\\\\ PG~(+1, -2, +4, -8, +16, -32, +64)\\\\\\\\ \Large\boxed{\boxed{Resposta~\to~~a_7=64}}$