Let:
[tex]\begin{gathered} (x1,y1)=(0,-8) \\ (x2,y2)=(4,8) \end{gathered}[/tex]
The slope m is given by:
[tex]\begin{gathered} m=\frac{y2-y1}{x2-x1} \\ m=\frac{8-(-8)}{4-0} \\ m=\frac{16}{4} \\ m=4 \end{gathered}[/tex]
Using the point-slope equation:
[tex]\begin{gathered} y-y1=m(x-x1) \\ y-(-8)=4(x-0) \\ y+8=4x \\ y=4x-8 \end{gathered}[/tex]
