Question 1121707
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Let *[tex \Large r] represent the speed of the southbound boat.  Then *[tex \Large r\ +\ 7] is the speed of the eastbound boat.  After 4 hours, the southbound boat will have traveled *[tex \Large 4r] miles and the eastbound boat will have traveled *[tex \Large 4r\ +\ 28] miles.  Now you have a right triangle with legs of *[tex \Large 4r] and *[tex \Large 4r\ +\ 28] miles and a hypotenuse of 52 miles.


According to Pythagoras, who should be a very old and dear friend of yours by now,


*[tex \LARGE \ \ \ \ \ \ \ \ \ \  \(4r\ +\ 28\)^2\ +\ \(4r\)^2\ =\ 52^2]


Expand, collect like terms, put into standard form, and solve the quadratic equation for *[tex \Large r].
								
								
John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
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