Answer:
r = 13
Step-by-step explanation:
The first step is to find b from y=mx=b using m=4/3 and (-4,8)
[tex]8=\frac{4}{3}(-4)+b[/tex]
After solving the equation, b will equal -16/3 making the final equation be
[tex]y=\frac{4}{3} x-\frac{16}{3}[/tex]
Using the equation, you can solve for r.
[tex]12=\frac{4}{3} x-\frac{16}{3}[/tex]
This will bring the answer being r = 13