document.write( "Question 1058969: how many gallons of acid need to be addedto convert one gallon 20% acid soltion into 30% acid solution. \n" ); document.write( "

Algebra.Com's Answer #674035 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+x+\"$ = gallons of pure acid to be added
\n" ); document.write( " $\"+.2%2A1+=+.2+\"$ gallons of acid in original solution
\n" ); document.write( "----------------------------------------------
\n" ); document.write( " $\"+%28+x+%2B+.2+%29+%2F+%28+x+%2B+1+%29+=+.3+\"$
\n" ); document.write( " $\"+x+%2B+.2+=+.3%2A%28+x+%2B+1+%29+\"$
\n" ); document.write( " $\"+x+%2B+.2+=+.3x+%2B+.3+\"$
\n" ); document.write( " $\"+.7x+=+.1+\"$
\n" ); document.write( " $\"+x+=+1%2F7+\"$
\n" ); document.write( "----------------
\n" ); document.write( "1/7 gallon of pure acid needs to be added
\n" ); document.write( "( about .1429 gallons )
\n" ); document.write( "--------------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+x+%2B+.2+%29+%2F+%28+x+%2B+1+%29+=+.3+\"$
\n" ); document.write( " $\"+%28+1%2F7+%2B+1%2F5+%29+%2F+%28+1%2F7+%2B+1+%29+=+3%2F10+\"$
\n" ); document.write( " $\"+%28+5%2F35+%2B+7%2F35+%29+%2F+%28+8%2F7+%29+=+3%2F10+\"$
\n" ); document.write( " $\"+%28+12%2F35+%29+%2F+%28+40%2F35+%29+=+3%2F10+\"$
\n" ); document.write( " $\"+12%2F40+=+3%2F10+\"$
\n" ); document.write( " $\"+3%2F10+=+3%2F10+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );