document.write( "Question 324807: After 5 hours of house painting, Jess asked the assistance of Jon. Together, they finished the job in 4 more hours. Had Jon joined in an hour after Jess started working, the job would have been finished in 7 hours. How long would it have taken Jess to paint the house alone? \n" ); document.write( "
Algebra.Com's Answer #232570 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! After 5 hours of house painting, Jess asked the assistance of Jon. \n" ); document.write( " Together, they finished the job in 4 more hours. \n" ); document.write( "Had Jon joined in an hour after Jess started working, the job would have been finished in 7 hours. \n" ); document.write( " How long would it have taken Jess to paint the house? \n" ); document.write( ": \n" ); document.write( "Let x = Jess time painting the house alone \n" ); document.write( "Let y = Jon's time painting the house \n" ); document.write( "Let the completed job = 1 (a painted house) \n" ); document.write( ": \n" ); document.write( "Write an equation for each scenario \n" ); document.write( ": \n" ); document.write( "\"After 5 hours of house painting, Jess asked the assistance of Jon. Together, they finished the job in 4 more hours.\" \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "\"Had Jon joined in an hour after Jess started working, the job would have been finished in 7 hours.\" \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "We can combine the two equations \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "cross multiply \n" ); document.write( "y = 3x \n" ); document.write( ": \n" ); document.write( "Use substitution in the 1st equation \n" ); document.write( " \n" ); document.write( "multiply by 3x, results \n" ); document.write( "3(9) + 4 = 3x \n" ); document.write( "27 + 4 = 3x \n" ); document.write( "31 = 3x \n" ); document.write( "x = \n" ); document.write( "x = 10.3333 hrs (Jess time alone 10 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "check solution, find y \n" ); document.write( "y = 3(10.333) \n" ); document.write( "y = 31 hrs \n" ); document.write( ": \n" ); document.write( "check in the 2nd equation \n" ); document.write( " \n" ); document.write( ".714 + .226 = 1, confirms our solution\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |