Practice with Multiplying and Dividing Complex Numbers
Topic Index | Algebra2/Trig Index | Regents Exam Prep Center


Solve the following problems.  Answers are to be in simplest a+bi form.
  You should be able to solve the problems both with, and without,
your graphing calculator.

1.

 

     Multiply:   (3 + 5i)(3 - 5i)

Choose:

9 - 25i
25
34

 

 

2.

     Multiply:  (8 + 9i)(7 - 3i)

Choose:

15 - 12i
29 - 39i
83 + 39i

 

 

3.

Multiply:  (4 - 3i)(3 - 4i)

Choose:

25
-25i
12 - 12i

 

 

4.

Simplify:  (2 + 5i)2

Choose:

21 + 20i
-21 + 20i
29 + 20i

 

 

5.

Simplify:  8 + i(8 - i)

Choose:

7 + 8i
8 + 8i
9 + 8i

 

 

6.

     Simplify:

Choose:

5 - 2i
3 + 2i

15 + 10i

 

 

7.

      Simplify:   

Choose:

35/37 + (12/37)i
35 + 12i

35/36 + (12/36)i

 

 

8.

     Simplify: 

Choose:

5 + 3i
-5 - 3i
5 - 3i

 

 

9.

    Simplify: 

Choose:

2/15 + i/15
2/15 - i/15
1/45 + i/15

 

 

10.

What is the multiplicative inverse of

 

Choose:

2/(1 + i)
(1/2) - (1/2)i
(1 + i)/2