Question 997009
{{{system(k=6,h=14,d=40)}}}


Unknown variables are t, j, r.

<pre>
            speed       time     distance
TO           r           t        d
FROM         r-k         j        d
Total                    h
</pre>

The basic rate formula allows to find expressions for each of t and j.

<pre>
            speed       time        distance
TO           r           d/r         d
FROM         r-k         d/(r-k)     d
Total                    h
</pre>

Notice the total time sum and the indicated equation  {{{highlight(d/r+d/(r-k)=h)}}}.  Solve the equation for r.  Once the formula is simplified, substitute the given values and evaluate r.