Question

Which choice is equivalent to the expression below ?

Answer 1

Hi there!

Answer:

D. 9i

*The answer must have a positive sign.*

Explanation:

Lesson: Estimating and Comparing Square Roots.

Definition of Square Root

Square root- of a number is one of the number's two equal factors.

Every positive number has two square roots, one positive and one negative. The radical symbol,
`\sqrt{}`, indicates the non-negative or principle square root.

First, you apply radical rule

`√(-1)√(81)`

Then you apply imaginary by number rule.

`√(81)i`

`√(81)=9=9^2=9*9=81`

Therefore, the final answer is 9i.

I hope this helps you! :)

-Charlie

Thank you!