### Home > INT3 > Chapter 5 > Lesson 5.1.2 > Problem 5-38

5-38.

For homework, Crystal must simplify the expression

. She gets the answer 3, but when she checks, she learns that the correct answer is –3. Homework Help ✎ Show Crystal the steps she could take to get –3.

What steps do you think Crystal took to get 3 as a result?

What does she need to consider to avoid making this mistake in the future?

Crystal’s example means that

is not always true for real numbers *a*and*b*. What restriction needs to be placed on the numbers*a*and*b*?

What is (−3)(−3)?

She needs to convert to imaginary form before completing operations.

They must be non-negative real numbers.