Question 284297
<pre>
          SPEED          TIME    DISTANCE

Fred       r-0.5          4      (r-0.5)(4)

Desi       r              4      (r)(4)

TOTAL                               20
</pre>
{{{4(r-0.5)+4r=20}}}


{{{8r-2=20}}}

{{{4r-1=10}}}

{{{4r=11}}}

{{{r=11/4}}}

{{{highlight(r=2&3/4)}}}