Adding and Subtracting Complex Numbers

In the last lesson, we learned that the imaginary number "i" is the result when you take the square root of negative one.

In this lesson, we learn how to add and subtract complex numbers. This means we are going to learn how to combine like terms when we have multiple expressions involving "i".

Let's look at some examples of the types of problems that will be in this unit:

5 + 4i + 3
2i - 6 +3i
4i + 2 - 3i -7

When looking at complex numbers involving "i", it is easier to simplify each expressions if you replace "i" with variable "x". Then simplify the expression. Then just replace "x" with "i" when you are done.

In other words, variables are all equivalent as far as choosing the letter. It doesn't really matter what variable you use to label a number. 5x and 5m and 5i all mean the same thing at the base level.

So when simplyifying complex numbers, just pretend "i" is variable "x" and now all you have to do is combine like terms and you are done. Easy as pie.

The answer to problem #1 above is: 8 + 4i
The answer to problem #2 above is: -6 +5i
The answer to problem #3 above is: -5 + i

*Note: ALWAYS put the constant term first then the variable term second.

Adding and Subtracting Complex Numbers

In the last lesson, we learned that the imaginary number "i" is the result when you take the square root of negative one. In this lesson, we learn how to add and subtract complex numbers. This means we are going to learn how to combine like terms when we have multiple expressions involving "i".

In the last lesson, we learned that the imaginary number "i" is the result when you take the square root of negative one.

In this lesson, we learn how to add and subtract complex numbers. This means we are going to learn how to combine like terms when we have multiple expressions involving "i".