[tex] > \: resolucao \\ \\ \geqslant \: progressao \: \: geometrica \\ \\ q = \frac{a2}{a1} = \frac{ - 1}{ \frac{1}{2} } = - 1 \times \frac{2}{1} = - \frac{2}{1} = - 2 \\ \\ = = = = = = = = = = = = = = \\ \\ > \: o \: oitavo \: termo \: da \: pg \\ \\ an = a1 \times q {}^{n - 1} \\ an = \frac{1}{2} \times ( - 2) {}^{8 - 1} \\ an = \frac{1}{2} \times ( - 2) {}^{7} \\ an = \frac{1}{2} \times ( - 128) \\ an = - \frac{128}{2} \\ an = - 64 \\ \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant [/tex]