document.write( "Question 419040: The current of a river is 2 miles per hour. A boat travels to a point 8 miles upstream and back again in 3 hours. What is the speed of the boat in still water? \n" ); document.write( "
Algebra.Com's Answer #293134 by mananth(16946)\"\" \"About 
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speed in still water = x
\n" ); document.write( "current speed 2
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\n" ); document.write( "upstream speed = x-2
\n" ); document.write( "downstream speed = x+2
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\n" ); document.write( "Distance= 16 miles
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\n" ); document.write( "Time upstream + time downstream = 3hours
\n" ); document.write( "t=d/r
\n" ); document.write( "............
\n" ); document.write( "16/(x+2)+16/(x-2)=3
\n" ); document.write( "LCD = (x-2)(x +2)
\n" ); document.write( "16*(x-2)+16(x+2)=3
\n" ); document.write( "16x-32+ 16x+32=3(X^2-4)
\n" ); document.write( "32x=3X^2-12
\n" ); document.write( "3X^2-32 x-12=0 \r
\n" ); document.write( "\n" ); document.write( "Use the quadratic formula \r
\n" ); document.write( "\n" ); document.write( "b^2-4ac= 1168
\n" ); document.write( "x=(32+sqrt(1168))/6
\n" ); document.write( "11.03 mph speed in still water
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