Finding the formula with the parametric curve?

"The parametric curve given by x = t - 2 and y = 2t + 1 for t ∈ ℝ is also the graph of a function f(x). Find the formula for f(x)."

First of all, I would like to know that are these curves on the x-y plane or the x,y,z-plane? As I was confused as to whether you would have to sketch out the curves with finding the answer. Moreover, the answer, 2x + 5 does not include values of t but the equations for the parametric curve do. What I don't understand there is how you're able to find the formula by using the parametric curve?