To calculate the slope, we need the Delta Y over the Delta X.
So, the delta Y is: -2 - r
And the Delta X is: 3 - 5
We are left with:
\(\begin{array}{l}\frac{-2-r}{3-5}\ =\ -2\\ \\ =\ \frac{-2-r}{-2}=-2\\ =-2-r\ =\ 4\\ -r\ =\ 4\ +2\\ r\ =\ -6\\ \\ \\ \end{array}\)
Therefore the value of r = -6.
Heres the proof
(5, -6) --> (3, -2)
m = -2 - (-6) ÷ (3 - 5)
= 4 / -2 = -2.
Therefore r = -2
(Solved by a 12 y/o - Yep! )