[tex]\bf \begin{array}{ccll}x&y\\\cline{1-2}0&1\\[0.8em]1&\stackrel{2(1)+1}{3}\\[0.8em]2&\stackrel{2(2)+1}{5}\\[0.8em]3&\stackrel{2(3)+1}{7}\\[0.8em]x&2x+1\end{array}~\hspace{8em}y=2x+1[/tex]