document.write( "Question 136970: can you solve?
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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?
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document.write( "I am more interested in the work than the answer so please show me step by step.
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document.write( "Thanks \n" );
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Algebra.Com's Answer #100248 by checkley77(12844)![]() ![]() ![]() 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 \n" ); document.write( " \n" ); document.write( " |