recall the slope-intercept form.
ahemmm so, we know the slope, and we also know the y-intercept, thus the equation of that line is
[tex]\bf y=\stackrel{slope}{-\cfrac{2}{3}}x\stackrel{y-intercept}{+3}
\\\\\\
\textit{when x = 4, what is \underline{y}?}\qquad y=-\cfrac{2}{3}(4)+3\implies y=-\cfrac{8}{3}+3
\\\\\\
y=\cfrac{-8+9}{3}\implies y=\cfrac{1}{3}[/tex]
