Hi Madeline,
Yep, that is one of the possible correct answers. Do note that in such questions, there could be many possible answers, but as long as it satisfies the format Y=mX + c, where
Y and X - any combination of x, y or both or a known constants (like 2 or 3 etc) and
m and c - combination of known constants (a number like 2,3 etc) and unknown constants (a, b, c etc)
it will be acceptable.
But most of the time, the question will be such as to ask you to plot this against that. So, we just have to change the equation to fit the format given