Question 1001641
Basic uniform rates for travel, RT=D to relate rate, time, distance.

<pre>
            rate         time      distance
TO           r            12        d
FROM         r+20          8        d
</pre>

{{{system(r*12=d,(r+20)*8=d)}}}


Two equations in two unknown variables, but you want a value result for d, the distance.


{{{r=d/12}}}
-
{{{(d/12+20)*8=d}}}
{{{8d/12+160=d}}}
{{{8d+12*160=12d}}}----do any computations later if practical
{{{12*160=4d}}}
{{{12*40=d}}}
{{{highlight(d=480)}}}