To find the slope we need to apply:
[tex]\text{slope = m=}\frac{(y_2-y_1)}{(x_2-x_1)}[/tex]We have two points and we have:
[tex]\begin{gathered} (x_1,y_1)=(4,-8) \\ (x_2,y_2)=(-3,1) \\ \end{gathered}[/tex]Now we find m,
[tex]\begin{gathered} \text{m=}\frac{(y_2-y_1)}{(x_2-x_1)}=\frac{(1-(-8))}{(-3-4)}=\frac{1+8}{-7}=\frac{9}{-7}; \\ m=\frac{-9}{7} \end{gathered}[/tex]After that, we apply the general equation of the line:
[tex]\begin{gathered} (y-y_1)=m(x-x_1);_{}_{} \\ we\text{ replace the values for m,} \\ x_1=4 \\ y_1=-8 \\ (y-(-8))=\frac{-9}{7}(x-4); \\ y+8=\frac{-9}{7}x+\frac{36}{7} \\ \\ y=\frac{-9}{7}x+\frac{36}{7}-8 \\ y=\frac{-9}{7}x-\frac{20}{7} \end{gathered}[/tex]and from that, the intercept will be:
[tex]b=-\frac{20}{7}[/tex]