Let the two points in the graph are (0,7) and (1,3).
Then, the slope of the line is,
[tex]\begin{gathered} m=\frac{y_2-y_1}{x_2-x_1} \\ m=\frac{3-7}{1-0} \\ m=-4 \end{gathered}[/tex]Use the equation y=y1=m(x-x1) to find the equation of the line.
[tex]\begin{gathered} y-7=-4(x-0)\text{.} \\ y-7=-4x \\ y=-4x+7 \end{gathered}[/tex]Therefore, the equation of the line is y=-4x+7.