document.write( "Question 359035: I am not sure how to set this equation up? I am really getting frustrated and all I need help with is understanding how to use the D=r(t) table to set this up. Here is the question:\r
\n" ); document.write( "\n" ); document.write( "Junior’s boat will go 15 miles per
\n" ); document.write( "hour in still water. If he can go 12 miles downstream in the
\n" ); document.write( "same amount of time as it takes to go 9 miles upstream,
\n" ); document.write( "then what is the speed of the current?\r
\n" ); document.write( "\n" ); document.write( "Here is what I have so far:\r
\n" ); document.write( "\n" ); document.write( "D R T
\n" ); document.write( "12mile 15mph = 3/5 hr
\n" ); document.write( "9miles 15mph = 4/5 hr\r
\n" ); document.write( "\n" ); document.write( "Is this correct or am I making an error somewhere is setting this up? \n" ); document.write( "

Algebra.Com's Answer #256229 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!


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document.write( "Hi,
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document.write( "distance formula: d = rt   t = d/r
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document.write( "Letting c be the rate of the current
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document.write( "12 miles downstream in the 'same amount of time' as it takes to go 9 miles upstream
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document.write( "
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document.write( "Cross multiplying to solve for c
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document.write( "12(15 -c ) = 9(15+c)
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document.write( "12*15mph - 9*15mph = 2c
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document.write( "45 = 2c
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document.write( "22.5mph= c \n" );
document.write( "

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