### Home > PC > Chapter 11 > Lesson 11.1.3 > Problem11-48

11-48.
1. Multiply each of the following complex numbers. Recall that i = and i2 = −1. Homework Help ✎

1. (3 + 2i) (3 − 2i)

2. What does + 7i need to be multiplied by so that the result will be a whole number?

3. What does a + bi need to be multiplied by so that the result will be a whole number?

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Did you remember to use the Distributive Property?

$(\sqrt{5})(\sqrt{5})+(\sqrt{5})(\textit{i}\sqrt{3})-(\textit{i}\sqrt{3})(\sqrt{5})-(\textit{i}\sqrt{3})(\textit{i}\sqrt{3})$

The answers for parts (a) and (b) are both whole numbers. How are the factors being multiplied the same or different?