Concepts in complex numbers

Given the complex number  $-23+5i$  , what is the real part and what is the imaginary part

• Real: -23 and Imaginary: 5

• Real: 23 and Imaginary: -5

• Real: 5 and Imaginary: 23

• Real: -5 and Imaginary: 23

5. The expression  $\frac{\sqrt{-50}}{\sqrt{2}}$  is equivalent to...

• -5i

• -5

• 5i

• 5

What is standard form?

• a+bi

• bi+a

• ai+b

• b+ai

 $-\sqrt{144}$  

• 12

• -12

• -72

• none of the above (imaginary number) 

Select all expressions below that are considered complex numbers. Refer to the table in the notes.

• 3 + 2i

• 2

• 3

• -6i

 $What\ is\ the\ sum\ of\ \sqrt{-2\ }and\ \sqrt{-18}?$  

•  $4\sqrt{2}$  

•  $4\sqrt{2}i$  

•  $5\sqrt{2}i$  

•  $5\sqrt{2}$  

True or False:
An imaginary number is any number that can be written in the from a + bi, where a and b are real numbers and 

b  $\ne$  0. 

• True

• False

In the Complex Number 4 - 8i, what is the imaginary part?

• 4

• -8

• -8i

• 8i