<PRE><B>Question 419040</B>
Same distance 8 miles each way
s, speed of boat in still water
3 hours, total travel time


time = distance/speed
account for total travel time


{{{8/(s+2)+8/(s-2)=3}}}
Some steps, becomes a quadratic equation.  Solve.


{{{8(s-2)+8(s+2)=3(s+2)(s-2)}}}

{{{16s-16+16=3(s^2-4)}}}

{{{16s=3s^2-12}}}

{{{3s^2-16s-12=0}}}
Try factoring.  If not, use quadrati formula solution.


{{{s=(16+- sqrt(16^2+4*3*12))/(2*3)}}}

{{{s=(16+sqrt(400))/(2*3)}}}

{{{s=(16+20)/6}}}

{{{s=36/6}}}

{{{s=6}}} which also check in the original equation.</PRE>