You may want to review multiplying complex numbers first.

Dividing complex numbers requires a trick. Suppose you need to
divide (5 − 2*i*) / (−1 − 4*i*). You
multiply the numerator and the denominator both by −1 +
4*i*. This is called the *conjugate* of the
denominator; in general, the conjugate of a complex number is what
you get when you switch the sign in the middle. This gives you 3
+ 22*i* in the numerator, but 17 in the denominator. Now, the
denominator's a real number, so we can divide; just divide each
term of the (new) numerator by 17. So the answer is
3 ⁄ 17 + 22 ⁄ 17
* *i*. This always works, since the product of a number and
its conjugate is always real.

If the denominator is just something times *i*, then its
conjugate is just its additive inverse; so the conjugate of
2*i* is −2*i*.