Complex Numbers : Dividing Complex Numbers Quiz

Complex numbers contain a real number and an imaginary number and are written in the form a+bi. Remember that i^2 = -1. Below is a worked example of how to divide complex numbers.

Solve.
(6+3i) / (7+5i)

Step 1. Multiply both terms by the denominator but change the sign.

(6+3i)(7-5i) / (7+5i)(7-5i)

Step 2. Use the FOIL method to expand the numerator and denominator.

42+30i+21i+15(i^2) / 49-25(i^2)

Step 3. Group like terms. Remember i^2 = -1

42+15(-1)+51i / 49-25(-1)

Step 4. Simply.

42-15+51i / 49+25

27+51i / 74

Step 5. Write in standard form.

27/74 + 51/74i

Good luck!!!