[tex]\begin{gathered} m=\frac{rise}{run} \\ rise=y2-y1 \\ run=x2-x1 \end{gathered}[/tex]
For the red line:
[tex]\begin{gathered} rise=4-(-2)=6 \\ run=2-0=2 \\ m=roc=\frac{6}{2}=3 \end{gathered}[/tex]
For the blue line:
[tex]\begin{gathered} rise=-8-4=-12 \\ ru_{}n=-4-0=-4 \\ m=roc=\frac{-12}{-4}=3 \end{gathered}[/tex]
Therefore, they have the same roc
