document.write( "Question 65067: Karen and John take 3 hours to clean the house. Karen alone can clean the house 1 hour faster than John can clean the house alone. What is the total time it takes Karen to clean the house alone. \n" ); document.write( "
Algebra.Com's Answer #45585 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Karen and John take 3 hours to clean the house. Karen alone can clean the house 1 hour faster than John can clean the house alone. What is the total time it takes Karen to clean the house alone. \n" ); document.write( "---------- \n" ); document.write( "Karen/John together DATA: \n" ); document.write( "time=3 hrs/job; rate=(1/3)job/hr. \n" ); document.write( "-------------------- \n" ); document.write( "John alone DATA: \n" ); document.write( "time= x hrs/job; rate = (1/x)job/hr. \n" ); document.write( "-------------------- \n" ); document.write( "Karen alone DATA: \n" ); document.write( "time = (x+1) hr/job ; rate = 1/(x+1) job/hr \n" ); document.write( "-------- \n" ); document.write( "EQUATION: \n" ); document.write( "rate + rate = rate together \n" ); document.write( "(1/x)+1/(x+1)= 1/3 \n" ); document.write( "Multiply thru by 3x(x+1) to get: \n" ); document.write( "3(x+1)+3x = x(x+1) \n" ); document.write( "6x+3=x^2+x \n" ); document.write( "x^2-5x-3=0 \n" ); document.write( "x=[5+-sqrt(25-4*-3)]/2 \n" ); document.write( "x=[5+-sqrt(37)]/2 \n" ); document.write( "x= 5.541 hrs \n" ); document.write( "x+1=6.541 hrs (Time it takes Karen alone to clean the house) \n" ); document.write( "Cheers, \n" ); document.write( "Stan H.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |