Respuesta :

5. D (the number under the square root symbol must be greater than or equal to 0. 


Answer:

The domain of the function is x>=-7

Step-by-step explanation:

The domain is all the values that x can take so the function is defined, that means we can find a value of y

The sqrt is defined only for positive values and zero. So the expression in the sqrt must  satisfy that

6x + 42 >=0

We only have to find x

6x >=-42

x>=-42/6

x>=-7

So the answer is D x>=-7