document.write( "Question 1151235: How many gallons of 40% alcohol solution must be mixed with 70% solution to obtain 30 gallons of 52% alcohol solution? \n" ); document.write( "

Algebra.Com's Answer #772911 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = gallons of 40% alcohol needed
\n" ); document.write( " $\"+30+-+x+\"$ = gallons of 70% alcohol needed
\n" ); document.write( "----------------------------------------------------
\n" ); document.write( " $\"+%28+.4x+%2B+.7%2A%28+30+-+x+%29+%29+%2F+30+=+.52+\"$
\n" ); document.write( " $\"+%28+.4x+%2B+21+-+.7x+%29+%2F+30+=+.52+\"$
\n" ); document.write( " $\"++21+-+.3x+=+15.6+\"$
\n" ); document.write( " $\"+.3x+=+5.4+\"$
\n" ); document.write( " $\"+x+=+18+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+30+-+x+=+12+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "18 gallons of 40% alcohol are needed
\n" ); document.write( "-----------------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+.4x+%2B+.7%2A%28+30+-+x+%29+%29+%2F+30+=+.52+\"$
\n" ); document.write( " $\"+%28+.4%2A18+%2B+.7%2A12+%29+%2F+30+=+.52+\"$
\n" ); document.write( " $\"+%28+7.2+%2B+8.4+%29+%2F+30+=+.52+\"$
\n" ); document.write( " $\"+15.6+%2F+30+=+.52+\"$
\n" ); document.write( " $\"+15.6+=+15.6+\"$
\n" ); document.write( "OK \n" ); document.write( "

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