document.write( "Question 414226: How many gallons of a 3% salt solution must be mixed with 30 gallons of a 9% solution to obtain a 6% solution? \n" ); document.write( "

Algebra.Com's Answer #290518 by dnanos(83) $\"\"$ $\"About$

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We need,
\n" ); document.write( "X gallons 3%
\n" ); document.write( "and
\n" ); document.write( "30 gallons 9%
\n" ); document.write( "to obtain,
\n" ); document.write( "30+x gallons 6%
\n" ); document.write( "so
\n" ); document.write( "because the pure salt weight before and after mixing remains equal
\n" ); document.write( "we have the following equation.
\n" ); document.write( "(3/100)*x+ (9/100)*30=(6/100)*(30+x)
\n" ); document.write( "multiply by 100
\n" ); document.write( "3x+9*30=6(30+x)
\n" ); document.write( "3x+270=180+6x
\n" ); document.write( "3x-6x=180-270
\n" ); document.write( "-3x=-90
\n" ); document.write( "3x=90
\n" ); document.write( "3x/3=90/3
\n" ); document.write( "x=30
\n" ); document.write( "So we need 30 gallons of 3% ... \n" ); document.write( "

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