Question 1077421
<pre>
                 SPEED    TIME     DISTANCE
Short route        r        t        7
Longer route       r       t+1      14
</pre>


{{{system(r(t+1)=14,and, rt=7)}}}


{{{rt+r=14}}}
{{{7+r=14}}}
{{{r=14-7}}}
{{{highlight(r=7)}}}