Question 1112541
<pre>
                       SPEEDS       TIMES       DISTANCE
GOING                    r           10          d=10r
RETURN                 r+18           7          d=7(r+18)
</pre>

The question asks for d.


{{{r=d/10}}}
-
{{{d=7(r+18)}}}
{{{d=7r+7*18}}}
{{{d=7(d/10)+7*18}}}
{{{10d=7d+7*18*10}}}
{{{3d=7*3*6*10}}}
{{{d=7*6*10}}}
{{{highlight(d=420)}}}