document.write( "Question 200899: Ann and betty work together and complete a sales report in 4 hr. It would take Betty 6 hr longer, working alone to do the job than it would Ann. How long would it take each of them to do the job working alone. \n" ); document.write( "
Algebra.Com's Answer #151130 by ptaylor(2198)![]() ![]() You can put this solution on YOUR website! Let x=amount of time it takes Ann working alone \n" ); document.write( "Then Ann works at the rate of 1/x of the report per hour \n" ); document.write( "Let (x+6)= amount of time it takes Betty working alone \n" ); document.write( "Then Betty works at the rate of 1/(x+6) of the report per hour\r \n" ); document.write( "\n" ); document.write( "Now we are told that Ann and Betty can do the report working together in 4 hours. So Ann and Betty together works at the rate of 1/4 of the report per hour \n" ); document.write( "So we have: \n" ); document.write( "1/x + 1/(x+6)= 1/4 Multiply each term by 4x(x+6) \n" ); document.write( "4(x+6)+4x=x(x+6) get rid of parens \n" ); document.write( "4x+24+4x=x^2+6x subtract x^2 and also 6x from each side \n" ); document.write( "4x+24+4x-x^2-6x=x^2+6x-x^2-6x collect like terms \n" ); document.write( "-x^2+2x+24=0 multiply each term by -1 \n" ); document.write( "x^2-2x-24=0-------------------quadratic in standard form and it can be factored \n" ); document.write( "(x-6)(x+4)=0 \n" ); document.write( "x=6 and \n" ); document.write( "x=-4 disregard the negative value for x time in this problem is positive\r \n" ); document.write( "\n" ); document.write( "x=6 hrs----amount of time it takes Ann working alone \n" ); document.write( "x+6=6+6=12 hours amount of time it takes Betty working alone\r \n" ); document.write( "\n" ); document.write( "CK \n" ); document.write( "1/6 + 1/12=1/4 \n" ); document.write( "2/12 +1/12=1/4 \n" ); document.write( "3/12=1/4 \n" ); document.write( "1/4=1/4\r \n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor \n" ); document.write( " |