Question 1199205
.
<pre>

Using coordinates of the points, write equation for the slope

    {{{(3-2)/(5-R)}}} = {{{1/2}}}.


From this equation, find the unknown value of R. For it, first cross-multiply; then simplify

    2*(3-2) = 5 - R

    2       = 5 - R

    R       = 5 - 2 = 3.


<U>ANSWER</U>.  R = 3.
</pre>

Solved.