Simplify. Write your answers in the form of a+bi, where a and b are real numbers.
-$$( 3 + 3 i ) ( 3 - 3 i )$$
A) $9 - 9 \mathrm { i }$
B) $9 + 9 \mathrm { i }$
C) 0
D) 18

Question

Quizplus · Accepted Answer

Using the formula for multiplying complex numbers $(a+bi)(c+di) = (ac-bd) + (ad+bc)i$, we get $(3+3i)(3-3i) = (3*3 - 3*(-3)) + (3*(-3) + 3*3)i = 9 + 9 + 0i = 18$.

Simplify Write Your Answers in the Form of A+bi, Where (3+3i)(3−3i)( 3 + 3 i ) ( 3 - 3 i )(3+3i)(3−3i)

Simplify Write Your Answers in the Form of A+bi, Where $( 3 + 3 i ) ( 3 - 3 i )$