document.write( "Question 136970: can you solve?
\n" ); document.write( "A boat moves 7kph in still water. It ravels 45 km upriver and 45 km downriver in a total time of 14 hours. What is the speed of the current?
\n" ); document.write( "I am more interested in the work than the answer so please show me step by step.
\n" ); document.write( "Thanks
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Algebra.Com's Answer #100248 by checkley77(12844)\"\" \"About 
You can put this solution on YOUR website!
d=rt or d/r=t
\n" ); document.write( "45/(7+x)+4/(7-x)=14
\n" ); document.write( "[45(7-x)+45(7+x)]/(7+x)(7-x)=14
\n" ); document.write( "[315-45x+315+45x]/(49-x^2)=14
\n" ); document.write( "630/(49-x^2)=14 now cross multiply
\n" ); document.write( "14(49-x^2)=630
\n" ); document.write( "686-14x^2=630
\n" ); document.write( "-14x^2=630-686
\n" ); document.write( "-14x^2=-56
\n" ); document.write( "x^2=-56/-14
\n" ); document.write( "x^2=4
\n" ); document.write( "x=sqrt4
\n" ); document.write( "x=2 kmph is the speed of the current.
\n" ); document.write( "45/(7+2)+45/(7-2)=14
\n" ); document.write( "45/9+45/5=14
\n" ); document.write( "5+9=14
\n" ); document.write( "14=14
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