document.write( "Question 511241: A radiator contains 9 quarts of fluid, 40% of which is antifreeze. How much fluid should be drained and replaced with pure antifreeze so that the new mixture is 55% antifreeze? \n" ); document.write( "

Algebra.Com's Answer #342083 by josmiceli(19441) $\"\"$ $\"About$

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In words:
\n" ); document.write( "( final quarts of antifreeze) / ( final quarts of fluid ) = 55%
\n" ); document.write( "Let $\"+x+\"$ = quarts of fluid to be drained
\n" ); document.write( "and replaced with pure antifreeze
\n" ); document.write( "given:
\n" ); document.write( " $\"+.4%2A9+=+3.6+\"$ = quarts of antifreeze in original mixture
\n" ); document.write( " $\"+.4x+\"$ = quarts of antifreeze that is drained off
\n" ); document.write( "------------
\n" ); document.write( " $\"+%28+3.6+-+.4x+%2B+x+%29+%2F+9+=+.55+\"$
\n" ); document.write( " $\"+%28+3.6+%2B+.6x+%29+%2F+9+=+.55+\"$
\n" ); document.write( " $\"+3.6+%2B+.6x+=+4.95+\"$
\n" ); document.write( " $\"+.6x+=+4.95+-+3.6+\"$
\n" ); document.write( " $\"+.6x+=+1.35+\"$
\n" ); document.write( " $\"+x+=+2.25+\"$
\n" ); document.write( "2.25 quarts of fluid should be drained
\n" ); document.write( "and replaced with pure antifreeze
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+3.6+%2B+.6%2A2.25+%29+%2F+9+=+.55+\"$
\n" ); document.write( " $\"+%28+3.6+%2B+1.35+%29+%2F+9+=+.55+\"$
\n" ); document.write( " $\"+4.95+%2F+9+=+.55+\"$
\n" ); document.write( " $\"+4.95+=+4.95+\"$
\n" ); document.write( "OK \n" ); document.write( "

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