Respuesta :

Answer:

r = 1

Step-by-step explanation:

we know that :

[tex]Slope=\frac{y_{B}-y_{A}}{x_{B}-x_A}[/tex]

Then

[tex]\frac{5}{4} =\frac{16-r}{-3-(-15)}[/tex]

Then

[tex]\frac{5}{4} =\frac{16-r}{12}[/tex]

Then

5×12 = 4×(16-r)

Then

60 = 64 - 4r

Then

4r = 64 - 60

Then

4r = 4

Then

r = 1