Correct. Treat the division as a fraction and simplify. If there is still an i in the denominator, rationalize it.

$\displaystyle\frac{{42}}{{{3}{i}}}=\frac{{3}}{{3}}\cdot\frac{{14}}{{i}}=\frac{{14}}{{i}}\usepackage{cmbright}\Huge\$

$\displaystyle\frac{{14}}{{i}}\cdot\frac{{i}}{{i}}=\frac{{{14}{i}}}{{{{i}}^{{2}}}}=\frac{{{14}{i}}}{{-{1}}}=-{14}{i}\usepackage{cmbright}\Huge\$