The slope is given by:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
from the graph we notice that the line passes through the points (0,2) and (3,0), plugging this values into the equation above we have:
[tex]\begin{gathered} m=\frac{0-2}{3-0} \\ m=-\frac{2}{3} \end{gathered}[/tex]
therefore the slope is m=-2/3.
The y intercept is the value of y when x=0; from the graph we conclude that b=2.
The equation of the line is:
[tex]y=-\frac{2}{3}x+2[/tex]
