Question 1049079
Constant Travel Rate Rule to relate rate, time, distance corresponding to R, T, D,  is RT=D.

<pre>
                SPEED           TIME         DISTANCE
UPSTREAM        x-y             6            528
DOWNSTR         x+y             5.5          528
</pre>


You have a system of equations,  {{{system((x-y)*6=528,(x+y)*(5.5)=528)}}}.
Solve the system.  Both equations are linear.