document.write( "Question 206942: two technicians can complete a mailing in 3 hours when working together. alone, one can complete the mailing 2 hours faster than the other. how long will it take each person to complete the mailing alone? compute answer to two decimal places. \n" ); document.write( "
Algebra.Com's Answer #156453 by Theo(13342) You can put this solution on YOUR website! let x = rate of first technician \n" ); document.write( "let y = rate of second technician. \n" ); document.write( "----- \n" ); document.write( "working together they can complete a mailing in 3 hours. \n" ); document.write( "(x + y) * 3 = 1 \n" ); document.write( "(x + y) is their combined rate. \n" ); document.write( "3 = number of hours \n" ); document.write( "1 = units produced. \n" ); document.write( "----- \n" ); document.write( "they produced 1 unit of mailing in 3 hours working together. \n" ); document.write( "----- \n" ); document.write( "let the first technician be the faster mailer. \n" ); document.write( "the first technician works at a rate of x mailings per hour. \n" ); document.write( "the second technician works at a rate of y mailings per hour. \n" ); document.write( "----- \n" ); document.write( "alone, the first technician can complete the mailing 2 hours faster than the other. \n" ); document.write( "----- \n" ); document.write( "let h = amount of time in hours it takes for the first technician to complete the mailing. \n" ); document.write( "----- \n" ); document.write( "x * h = 1 mailing \n" ); document.write( "----- \n" ); document.write( "since the first technician can complete the mailing in 2 hours less than the second technician, then (h+2) represents the time it takes the second technician to complete the mailing. \n" ); document.write( "----- \n" ); document.write( "y * (h+2) = 1 mailing \n" ); document.write( "----- \n" ); document.write( "since x * h = 1, then x = (1/h) which looks like \n" ); document.write( "----- \n" ); document.write( "since y * (h+2) = 1, then y = (1/(h+2)) which looks like \n" ); document.write( "----- \n" ); document.write( "formula of (x+y)*3 = 1 becomes ((1/h) + (1/(h+2))) * 3 = 1 \n" ); document.write( "this looks like \n" ); document.write( "----- \n" ); document.write( "multiply both sides of this equation by (h)*(h+2) to get ((h+2) + (h)) * 3 = (h)*(h+2) \n" ); document.write( "this looks like \n" ); document.write( "----- \n" ); document.write( "this becomes 6h + 6 = h^2 + 2h which looks like \n" ); document.write( "----- \n" ); document.write( "this eventually results in h^2 - 4h - 6 = 0 which looks like \n" ); document.write( "----- \n" ); document.write( "using the quadratic formula, the roots are either: \n" ); document.write( "h = 5.16227766 or h = -1.16227766 \n" ); document.write( "----- \n" ); document.write( "since h can't be negative, the only possible answer is h = 5.16227766 \n" ); document.write( "----- \n" ); document.write( "if h = 5.16227766, then x = 1/5.16227766 = .193712943 and y = 1/7.16227766 = .13962039 \n" ); document.write( "----- \n" ); document.write( "to test this out, we substitute for x and h in the equations we created that contain h in them. \n" ); document.write( "----- \n" ); document.write( "first equation is \n" ); document.write( "----- \n" ); document.write( "this becomes \n" ); document.write( "which results in 1 = 1 proving the value of h is correct. \n" ); document.write( "----- \n" ); document.write( "second equation is x * h = 1. \n" ); document.write( "x = .193712943 \n" ); document.write( "h = 5.16227766 \n" ); document.write( "x * h = 1 proving the values for x and h are good. \n" ); document.write( "----- \n" ); document.write( "third equation is y * (h+2) = 1. \n" ); document.write( "y = .13962039 \n" ); document.write( "h + 2 = 7.16227766 \n" ); document.write( "y * (h+2) = 1 proving the values for y and (h+2) are good. \n" ); document.write( "----- \n" ); document.write( "we started off with \n" ); document.write( "we then got \n" ); document.write( "we then got \n" ); document.write( "we then got \n" ); document.write( "we then got \n" ); document.write( "we then substituted in \n" ); document.write( "we then solved for h. \n" ); document.write( "----- \n" ); document.write( "once we solved for h we were then able to complete the problem. \n" ); document.write( "----- \n" ); document.write( " |