Question 153822
1)
For {{{sqrt(x)}}} to be a real number, x has to be greater or equal to 0.
2) 
For {{{5 - sqrt(x)}}} to be a real number, x has to be greater or equal to 0.
3)
For {{{sqrt(x+3)}}} to be a real number, x+3 has to be greater or equal to 0.
I.e., x+3 >=0
Solving the inequality for x, we have
x>=-3