The equation of the line with a given point and a slope is given as:
[tex]\begin{gathered} y-y_1=m(x-x_1) \\ x_1=0;y_1=0 \\ m=-3 \end{gathered}[/tex]
Thus, we have the equaton of the line to be:
[tex]\begin{gathered} y-0=-3(x-0) \\ y=-3x \end{gathered}[/tex]
The graph of the line y = -3x is shown below:
