Question

How do you find the domain and range of `y = 3x + 8`?

Answer 1

I found all the real `x` and all the real `y`.

Explanation:

Your equation represents, graphically a straight, line of slope `3` and passing through `x=0,y=8`.

graph{3x+8 [-10, 10, -5, 5]}

It can accept any real `x` value and gives you, as a result, any real `y` value; so the domain is all the real `x` and range all the real `y`.