Question 965093
r, boat speed when no river current
c, speed of river current
u, time upstream
v, time downstream
d, the one-way trip distance


RT=D for rate time distance relationship



____________________rate____________time__________distance
UPSTREAM____________r-c_____________u____________(r-c)*u=d
DOWNSTREAM__________r+c_____________v____________(r+c)*v=d


Solve for c.
{{{(r-c)*u=(r+c)*v}}}