Question

Express 1-2i divided by 1+2i in a+ib form​

Answer 1

Explanation:

$\frac{1 - 2i}{1 + 2i} \times \frac{1 - 2i}{1 - 2i} \\ = \frac{1 - 4 + 4i}{1 + 4} \\ = \frac{ - 3 + 4i}{5} \\ = \frac{ - 3}{5} + \frac{4i}{5}$