document.write( "Question 699066: \"This is the problem. Would you please help me with this? Thank You!\" ---> A and B working together can finish a certain job in 20/3 hours. They start the work together but after 3 hours. A became ill and B continuing the work alone finished it in 33/4 hours. How long would it take each working alone to do the job? \n" ); document.write( "
Algebra.Com's Answer #431291 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A and B working together can finish a certain job in 20/3 hours. \n" ); document.write( " They start the work together, but after 3 hours, A became ill and B continuing the work alone. finished it in 33/4 hours. \n" ); document.write( " How long would it take each working alone to do the job? \n" ); document.write( ": \n" ); document.write( "let a = A doing the job alone \n" ); document.write( "let b = B doing it alone \n" ); document.write( ": \n" ); document.write( "Let the completed job = 1 \n" ); document.write( ": \n" ); document.write( "Write a share work equation for the statement: \n" ); document.write( "\"A and B working together can finish a certain job in 20/3 hours.\" \n" ); document.write( " \n" ); document.write( "invert the divisor and multiply \n" ); document.write( " \n" ); document.write( "multiply by 3ab, results \n" ); document.write( "20b + 20a = 3ab \n" ); document.write( ": \n" ); document.write( "\" They start the work together but after 3 hours, A became ill and B continuing the work alone, finished it in 33/4 hours. How long would it take each working alone to do the job?\" \n" ); document.write( ": \n" ); document.write( "Change 33/4 hrs to 8.25 hrs \n" ); document.write( "B works 3 + 8.25 = 11.25 hrs \n" ); document.write( " \n" ); document.write( "multiply by ab to clear the denominators \n" ); document.write( "3b + 11.25a = ab \n" ); document.write( ": \n" ); document.write( "Try to use elimination with these two equations \n" ); document.write( "3b + 11.25a = ab \n" ); document.write( "20b + 20a = 3ab \n" ); document.write( "Multiply the 1st equation by 20, multiply the 2nd equation by 3 \n" ); document.write( "60b + 225a = 20ab \n" ); document.write( "60b + 60a = 9ab \n" ); document.write( "-----------------subtraction eliminates b \n" ); document.write( "165a = 11ab \n" ); document.write( "divide both side by a \n" ); document.write( "165 = 11b \n" ); document.write( "b = 165/11 \n" ); document.write( "b = 11 hrs working alone \n" ); document.write( ": \n" ); document.write( "Find a, \n" ); document.write( "20b + 20a = 3ab \n" ); document.write( "replace b with 11 \n" ); document.write( "20(11) + 20a = 3(a*11) \n" ); document.write( "220 + 20a = 33a \n" ); document.write( "220 = 33a - 20a \n" ); document.write( "220 = 13a \n" ); document.write( "a = 220/13 \n" ); document.write( "a = 16 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check this in the 1st work statement equation but we will use decimals instead of those annoying fractions \n" ); document.write( " \n" ); document.write( ".394 + .606 = 1; confirms our solutions\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |