Question

Me ajudem! (Números complexos).
Letra C e D

Answer 1

$c) \frac{z^-_1}{z_2} + \frac{z_1}{z_2} \\ \\ \frac{z_2(z^-_1 + z_1)}{z_2} \\ \\ \frac{(2 + i)(6 + 2i + 6 - 2i)}{2 + i} \\ \\ \frac{(2 + i)(12)}{2 + i} = \frac{(2 + i)(12)}{2 + i} .\frac{2-i}{2 - i} = \frac{(4 + 1)(12)}{4 + 1} = \frac{5.12}{5} = 12$

$d)\frac{z^-_1 + z^-_2}{z^-_2} = \frac{6 + 2i + 2 - i}{2 - i} = \frac{8 + i}{2 - i} \\ \\ \frac{8 + i}{2 - i}.\frac{2 + i}{2 + i} = \frac{16 + 18i -1}{4 + 1} = \frac{15 - 18i}{5} ===\ \textgreater \ \frac{15}{5} -i\frac{18}{5} ======\ \textgreater \ 3 - i \frac{18}{5}$