From the figure the given line passes through the points (0, 0) and (-4, 8).
Recall that the equation of a straight line is given by
[tex] \frac{y-y_1}{x-x_1} = \frac{y_2-y_1}{x_2-x_1} [/tex]
Thus, The equation of the given figure is given by
[tex]\frac{y-0}{x-0} = \frac{8-0}{-4-0}= \frac{8}{-4} \\ \\ -4y=8x \\ \\ y=-2x[/tex]