slope intercept equation is represented below
[tex]\begin{gathered} y=mx+b \\ \text{where} \\ m=\text{slope} \\ b=y-\text{intercept} \end{gathered}[/tex]Therefore,
[tex]\begin{gathered} 2=-\frac{1}{3}(0)+b \\ b=2 \\ y=-\frac{1}{3}x+2 \end{gathered}[/tex]