document.write( "Question 711002: A car radiator holds 2 gallons of fluid and initially is empty. If a mixture of water and antifreeze contains 70% antifreeze and another mixture contains 20% antifreeze, how much of each should be combined to fill the radiator with a 50% antifreeze mixture? \n" ); document.write( "

Algebra.Com's Answer #437257 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+x+\"$ = gallons of 70% antifreeze to be added
\n" ); document.write( " $\"+2+-+x+\"$ = gallons of 20% antifreeze to be added
\n" ); document.write( " $\"+.7x+\"$ = pure antifreeze in 70% mixture
\n" ); document.write( " $\"+.2%2A%28+2+-+x+%29+\"$ = pure antifreeze in 20% mixture
\n" ); document.write( "given:
\n" ); document.write( " $\"+%28+.7x+%2B+.2%2A%28+2+-+x+%29+%29+%2F+2+=+.5+\"$
\n" ); document.write( " $\"+%28+.7x+%2B+.4+-+.2x+%29+%2F+2+=+.5+\"$
\n" ); document.write( " $\"+.5x+%2B+.4+=+1+\"$
\n" ); document.write( " $\"+.5x+=+.6+\"$
\n" ); document.write( " $\"+x+=+1.2+\"$
\n" ); document.write( " $\"+2+-+x+=+.8+\"$
\n" ); document.write( "1.2 gallons of 70% antifreeze needs to be added
\n" ); document.write( ".8 gallons of 20% antifreeze needs to be added
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+.7x+%2B+.2%2A%28+2+-+x+%29+%29+%2F+2+=+.5+\"$
\n" ); document.write( " $\"+%28+.7%2A1.2+%2B+.2%2A%28+2+-+1.2+%29+%29+%2F+2+=+.5+\"$
\n" ); document.write( " $\"+%28+.84+%2B+.2%2A.8+%29+%2F+2+=+.5+\"$
\n" ); document.write( " $\"+%28+.84+%2B+.16+%29+%2F+2+=+.5+\"$
\n" ); document.write( " $\"+1%2F2+=+.5+\"$
\n" ); document.write( " $\"+.5+=+.5+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );