Question

Express $(-5i)\left(\frac{1}{8}i\right)$ in the form a + ib.

Answer 1

$(-5i)\left(\frac{1}{8}i\right)=-\frac{5}{8}{i}^2=-\frac{5}{8}(-1)=\frac{5}{8}$

which can also be written as $\frac{5}{8}+i\ast 0$