Respuesta :

Answer:

[tex]r=\frac{14}{3}[/tex]

Step-by-step explanation:

Set up an equation and solve for r using the formula for slope:

[tex]\frac{5-7}{r-4}=-3\\ \\-2=-3(r-4)\\\\-2=-3r+12\\\\-14=-3r\\\\\frac{14}{3}=r[/tex]