[tex]\bf \begin{array}{ccll}
x&y\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
0&\stackrel{0\cdot 7}{0}\\\\
1&\stackrel{1\cdot 7}{7}\\\\
2&\stackrel{2\cdot 7}{14}\\\\
3&\stackrel{3\cdot 7}{21}
\end{array}\qquad \qquad \implies y=x\cdot 7\implies y=7x[/tex]
