Concepts in complex numbers

Find the error and correct the problem:
-√-100 = -√-1 ∙ √100
           = i ∙10
        = 10i

• √100 ≠ 10
• They removed the negative sign in front of √-1
• √-1 ≠ i
• -√-100 ≠ -√-1 ∙ √100 

• 10

• -10

• The are no solutions

• 12

• -12

• 72

• none of the above (imaginary number)

Simplify  $3\sqrt{-9}$  

(a)  

Use square roots to solve this equation: x² = -18

• ±√-18

• ±i√18

• ±3i√2

• ±2i√3

Find the square root(s): -√121

• 11
• -11
• ±11
• none

√-81

• 9i
• -9i
• -9
• 9

the square root of -25 is..

• 5
• -5
• 8
• none of the above