document.write( "Question 821731: A pool can be filled with water by a large pipe within 6 hours. A smaller pipe will take 9 hours to fill the pool. How long will it take the pool if the two pipes operate together? \n" ); document.write( "
Algebra.Com's Answer #494364 by TimothyLamb(4379)\"\" \"About 
You can put this solution on YOUR website!
---
\n" ); document.write( "NOTE TO STUDENT:
\n" ); document.write( "rate = (one job) / (time required to do the job)
\n" ); document.write( "rate = job / time
\n" ); document.write( "r = j / t
\n" ); document.write( "for this problem, the job is to fill the pool
\n" ); document.write( "---
\n" ); document.write( "individual pipe rates:
\n" ); document.write( "r = 1/6
\n" ); document.write( "r = 1/9
\n" ); document.write( "---
\n" ); document.write( "the rates of both pipes filling the pool together:
\n" ); document.write( "r = 1/6 + 1/9
\n" ); document.write( "r = 9/(6*9) + 6/(6*9)
\n" ); document.write( "r = 9/54 + 6/54
\n" ); document.write( "r = 15/54
\n" ); document.write( "---
\n" ); document.write( "time per job is 1/r:
\n" ); document.write( "1/r = 1/(15/54)
\n" ); document.write( "1/r = 54/15
\n" ); document.write( "---
\n" ); document.write( "answer:
\n" ); document.write( "1/r = 3.6 hours to fill the pool
\n" ); document.write( "---
\n" ); document.write( "Solve and graph linear equations:
\n" ); document.write( "https://sooeet.com/math/linear-equation-solver.php
\n" ); document.write( "---
\n" ); document.write( "Solve quadratic equations, quadratic formula:
\n" ); document.write( "https://sooeet.com/math/quadratic-formula-solver.php
\n" ); document.write( "---
\n" ); document.write( "Solve systems of linear equations up to 6-equations 6-variables:
\n" ); document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php
\n" ); document.write( " \n" ); document.write( "
\n" );