Answer:
10
Step-by-step explanation:
Note that when there are two negative signs directly next to each other, you are adding:
[tex]\sqrt{99 - (-1)} = \sqrt{99 + 1} = \sqrt{100}[/tex]
Simplify:
[tex]\sqrt{100} = \sqrt{10 * 10} = 10[/tex]
10 is your value for the given expression
