y = -4x - 1
It is a linear function different from the constant function. Therefore, if the range is only one number, then the domain is only one number too.
Let's calculate it:
y = -25 → -4x - 1 = -25 |add 1 to both sides
-4x = -24 |divide both sides by (-4)
x = 6
Answer: The domain = {6}.