Let's find the slope M using the following equation:
[tex]\begin{gathered} M=\frac{y2-y1}{x2-x1} \\ \text{Where:} \\ x1=-1 \\ x2=2 \\ y1=3 \\ y2=8 \\ M=\frac{8-3}{2-(-1)}=\frac{5}{3} \end{gathered}[/tex]Now, let's use point slope equation:
[tex]\begin{gathered} y-y1=M(x-x1) \\ y-3=\frac{5}{3}(x-(-1)) \\ y-3=\frac{5}{3}x+\frac{5}{3} \\ \text{Solving for y:} \\ y=\frac{5}{3}x+\frac{5}{3}+3 \\ y=\frac{5}{3}x+\frac{14}{3} \end{gathered}[/tex]