Answer:
C. All real numbers except x=3.
Step-by-step explanation:
Domain is all the numbers that you can plug in and the expression will exist for that number you plugged in.
The given expression is a fraction. In a fraction, we have to worry about dividing by 0.
x-3 is 0 when x=0+3=3 (added 3 on both sides).
So the domain is all real numbers except x=3.
The reason we do not want to allow x to be 3 is because you will get:
[tex]\frac{2(3)}{3-3}=\frac{6}{0}[/tex] which is not defined.