Question 995323
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Let *[tex \Large r] represent the speed of the boat in still water and let *[tex \Large r_c] represent the speed of the current.


When the boat is going upstream, it is travelling at *[tex \Large r\ -\ r_c] with respect to the shoreline. When it is going downstream it is travelling at *[tex \Large r\ +\ r_c] with respect to the shoreline.


Since distance equals rate times time,


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 25\ =\ 5(r\ -\ r_c)]


describes the upstream trip and


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 65\ =\ 5(r\ +\ r_c)]


describes the downstream trip.


Solve the 2X2 system of equations for *[tex \Large r] and *[tex \Large r_c].  Hint, divide both sides of each equation by 5 and then solve by elimination.


John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it

*[tex \Large \ \
*[tex \LARGE \ \ \ \ \ \ \ \ \ \