The slope formula for 2 points is
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]where
[tex]\begin{gathered} (x_1,y_1)=(0,0) \\ (x_2,y_2)=(5,20) \end{gathered}[/tex]By substituting these values into the slope formula, we get
[tex]\begin{gathered} m=\frac{20-0}{5-0} \\ m=\frac{20}{5} \\ m=4 \end{gathered}[/tex]therefore, the slope is 4.