What is this? Please answer with an explanation

Answer:
see explanation
Step-by-step explanation:
Given
f(x) = - [tex]\sqrt{x+11}[/tex] - 3 ← substitute x = - 7
f(- 7) = - [tex]\sqrt{-7+11}[/tex] - 3
= - [tex]\sqrt{4}[/tex] - 3
= - 2 - 3
= - 5 ← output is real