Question 1065079
Their two separate distances are  {{{(r+7)*6}}} and {{{(r)(6)}}}.


Departure point and the two travel location points form a right triangle.


{{{(6(r+7))^2+(6r)^2=78^2}}}


{{{36(r^2+14r+49)+36r^2=78^2}}}

.
{{{r^2+14r+49+r^2=169}}}


{{{2r^2+14r+49-169=0}}}


{{{2r^2+14r-120=0}}}


{{{r^2+7r-60=0}}}
This is factorable.