document.write( "Question 404979: I could really use some help with this:\r
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document.write( "\"The sum of the numerator and denominator of a fraction is 40. If 3 is added to the numerator, and 2 added to the denominator, the new fraction is equal to 4/5. \r
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document.write( "What is the original fraction? \" \n" );
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Algebra.Com's Answer #286172 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! The sum of the numerator and denominator of a fraction is 40. If 3 is added to the numerator, and 2 added to the denominator, the new fraction is equal to 4/5. \n" ); document.write( "What is the original fraction? \" \n" ); document.write( "----------------- \n" ); document.write( "Let the original fraction be x/y. \n" ); document.write( "--- \n" ); document.write( "Equations: \n" ); document.write( "x + y = 40 \n" ); document.write( "(x+3)/(y+2) = 4/5 \n" ); document.write( "---- \n" ); document.write( "Modify the 2nd equation as follows: \n" ); document.write( "5(x+3) = 4(y+2) \n" ); document.write( "5x+15 = 4y+8 \n" ); document.write( "5x-4y = -7 \n" ); document.write( "------ \n" ); document.write( "Now, solve the system: \n" ); document.write( "x+y = 40 \n" ); document.write( "5x-4y = -7 \n" ); document.write( "--- \n" ); document.write( "Multiply the 1st equation by 5: \n" ); document.write( "5x + 5y = 5*40 \n" ); document.write( "5x-4y = -7 \n" ); document.write( "----- \n" ); document.write( "Subtract the bottom eq. from the top and solve for \"y\": \n" ); document.write( "9y = 207 \n" ); document.write( "y = 23 \n" ); document.write( "--- \n" ); document.write( "Solve for \"x\": \n" ); document.write( "x + y = 40 \n" ); document.write( "x + 23 = 40 \n" ); document.write( "x = 17 \n" ); document.write( "------- \n" ); document.write( "Original Fraction: 17/23 \n" ); document.write( "============================= \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "================ \n" ); document.write( " \n" ); document.write( " |