For homework, Londa was asked to simplify the expression
. She got the answer 7, but when she checked, she learned that the correct answer was −7. Homework Help ✎
Show Londa the steps she could take to get −7.
What steps do you think Londa took to get 7 as a result?
What does she need to consider in order to avoid making this mistake in the future?
Londa's example means that it is not always true that
for real numbers a and b. What restriction needs to be placed on the numbers a and b?
First eliminate the negative sign from each radical by replacing it with i.
Remember that i is the square root of −1, now finish multiplying.
See parts (a) and (b).
The variables a and b must be non-negative real numbers.