[tex]\bf \begin{array}{ccll}
x&y\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
1&30\\
2&35\\
3&40\\
4&45\\
a&5(a)+25
\end{array}\qquad \qquad y=5x+25[/tex]
if you have already covered slopes, you could also get it that way, in fact is simpler that way.
