Question 228255
Hint: remember that the formula {{{m=(y[2]-y[1])/(x[2]-x[1])}}} is used to find the slope. In this case, *[Tex \LARGE \left(x_{1}, y_{1}\right)] is the first point *[Tex \LARGE \left(5,r\right)] which means {{{x[1]=5}}} and {{{y[1]=7}}}.


Also *[Tex \LARGE \left(x_{2}, y_{2}\right)] is the second point *[Tex \LARGE \left(2,-3\right)] which means that {{{x[2]=2}}} and {{{y[2]=-3}}}.



Now plug these values along with {{{m=4/3}}} into the given slope formula to get: 


{{{4/3=(-3-r)/(2-5)}}}



I'll let you solve for 'r' from here.