First of all, remember what the equation of a line is:
y = mx+b
Where:
m is the slope, and
b is the y-intercept
m = 2/3
[tex]\begin{gathered} b=y-mx \\ b=4-2/3\cdot6 \\ b=4-4 \\ b=0 \end{gathered}[/tex]The equation of the line that passes through the point (6,4) with a slope of 2/3
[tex]y=\frac{2}{3}x[/tex]