What's the domain of:
Y=4 over x+5
do you mean y= 4/(x+5)? When the question asks for the domain, it is essentially asking what numbers I can plug into x to get a real number answer for y?
Hint: the denominator cannot equal to 0. You cannot divide anything by zero!
What values of x can you have that would not lead you to having a zero in the denominator?