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You can put this solution on YOUR website!
let x = time required by the smaller pipe to drain the pool alone
\n" ); document.write( "then
\n" ); document.write( "(x-12) = time required by the larger pipe
\n" ); document.write( "let completed job = 1; (a drained pool)
\n" ); document.write( ":
\n" ); document.write( "Two drain pipes can empty a pool in 17 1/2 minutes.
\n" ); document.write( " The larger pipe can empty the pool in 12 minutes less than it would take the smaller pipe.
\n" ); document.write( " How long will it take the smaller pipe to empty the pool alone?
\n" ); document.write( ":
\n" ); document.write( "
\n" ); document.write( "multiply equation by x(x-12),
\n" ); document.write( "x(x-12)*
\n" ); document.write( "cancel the denominators and you have:
\n" ); document.write( "17.5(x-12) + 17.5x = x(x-12)
\n" ); document.write( "17.5x - 210 + 17.5x = x^2 - 12x
\n" ); document.write( "combine to form a quadratic equation on the right
\n" ); document.write( "0 = x^2 - 12x - 35x + 210
\n" ); document.write( "x^2 - 47x + 210 = 0
\n" ); document.write( "you can use the quadratic formula here, but this will factor to
\n" ); document.write( "(x-5)(x-42) = 0
\n" ); document.write( "two solutions
\n" ); document.write( "x = 5; not possible
\n" ); document.write( "and
\n" ); document.write( "x = 42 min for small pipe to empty the pool alone
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "See if that checks out. large pipe, 42 - 12 = 30 min
\n" ); document.write( "
\n" ); document.write( ".417 + .583 = 1 \n" ); document.write( "