document.write( "Question 778533: two fishing boats depart a harbord at the same time, one traveling east, the other south. the eastbound boat travels at a speed 3 mi/h faster than the southbound boat. after two hours the boats are 30 mi apart. what is the speed of the boat going south? \n" ); document.write( "
Algebra.Com's Answer #474758 by lwsshak3(11628)\"\" \"About 
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two fishing boats depart a harbord at the same time, one traveling east, the other south. the eastbound boat travels at a speed 3 mi/h faster than the southbound boat. after two hours the boats are 30 mi apart. what is the speed of the boat going south?
\n" ); document.write( "***
\n" ); document.write( "let x=speed of southbound boat
\n" ); document.write( "x+3=speed of eastbound boat
\n" ); document.write( "distance=speed*traveling time
\n" ); document.write( "after 2 hrs:
\n" ); document.write( "southbound boat traveled 2x
\n" ); document.write( "eastbound boat traveled 2(x+3)=2x+6
\n" ); document.write( "you are working with a right triangle with legs of 2x and 2x+6 and hypotenuse=30
\n" ); document.write( "By the pythagorean theorem:
\n" ); document.write( "(2x)^2+(2x+6)^2=30^2
\n" ); document.write( "4x^2+4x^2+24x+36=900
\n" ); document.write( "8x^2+24x-864=0
\n" ); document.write( "x^2+3x-108=0
\n" ); document.write( "(x+12)(x-9)=0
\n" ); document.write( "x=-12 (reject, x>0)
\n" ); document.write( "or
\n" ); document.write( "x=9
\n" ); document.write( "speed of southbound boat=9 mph \n" ); document.write( "
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