First of all, we need to remember that in a direct variation, we have the following relationship between x and y:
[tex]\frac{y}{x}=\frac{8}{2}[/tex]Now, we simplify and make a cross multiplication and we have:
[tex]\begin{gathered} \frac{y}{x}=\frac{8}{2} \\ \frac{y}{x}=4 \\ y=4x \end{gathered}[/tex]The equation is y=4x, that is your answer.