Adding, Subtracting, & Multiplying Complex Numbers

Another way to express √-1 is?

• 1

• -1

• i

• 0

A complex number can be expressed as a + bi. What does a represent?

• the real part of the complex number

• the imaginary part of the complex number

• depends on the sign of the number

• the square root of the complex number

Simplify the expression:
 $\left(1\ +\ 5i\right)\ +\ \left(1\ -\ 5i\right)$  

•  $2\ +\ 10i$  

•  $2\ +\ 10i^2$  

•  $2$  

•  $-8$  

Simplify the expression:
 $\left(5\ +\ 4i\right)\ -\ \left(-1\ -\ 2i\right)$  

•  $6\ +6i$  

•  $4\ +\ 2i$  

•  $6\ -\ 6i$  

•  $4\ -\ 2i$  

Simplify the expression:
 $\left(8\ +\ 9i\right)\ +\ \left(4\ -\ 6i\right)$  

•  $17\ +\ 3i$  

•  $12\ +\ 3i^2$  

•  $17\ -2i$  

•  $12\ +\ 3i$  

Simplify. Write your answer in the form  $a+bi$  .

 $\left(2+4i\right)-\left(1-2i\right)$  

•  $3+2i$  

•  $1-2i$  

•  $1+6i$  

•  $10$  

Simplify √-4

• 2i

• -2i

• 2

• 4i

Calculate:
i + 6i

• 6i²

• 7i

• 5i

• 7i²

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• 
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What complex number is graphed here?

• -4+2i

• 2-4i

• 4-2i

• 2i-4