Question 1077431
<pre>
               SPEED       TIME      DISTANCE
AGAINST        r-9          t        4543
WITH W         r+9         t-18      4543
</pre>


System of equations:  {{{system(rt-9t=4543,rt+9t-18r=4705)}}}



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A POSSIBLE, NEATER WAY:

the difference between t and t-18 is  18.
{{{4543/(r-9)-4543/(r+9)=18}}}
Solve this equation for r.