document.write( "Question 993897: Manha wants to make a 36 percent acid solution. She has already 3 leters of a 72 percent acid solution. How many litres of a 9 percent acid solution must she add. \n" ); document.write( "

Algebra.Com's Answer #613116 by josmiceli(19441) $\"\"$ $\"About$

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$\"+.72%2A3+=+2.16+\"$ = liters of acid in 72% solution
\n" ); document.write( "Let $\"+x+\"$ = liters of 9% solution needed
\n" ); document.write( " $\"+.09x+\"$ = liters of acid in 9% solution
\n" ); document.write( "-----------------------------------
\n" ); document.write( " $\"+%28+2.16+%2B+.09x+%29+%2F+%28+3+%2B+x+%29+=+.36+\"$
\n" ); document.write( " $\"+2.16+%2B+.09x+=+.36%2A%28+3+%2B+x+%29+\"$
\n" ); document.write( " $\"+2.16+%2B+.09x+=+1.08+%2B+.36x+\"$
\n" ); document.write( " $\"+.27x+=+1.08+\"$
\n" ); document.write( " $\"+x+=+4+\"$
\n" ); document.write( "4 liters of 9% solution are needed
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+2.16+%2B+.09x+%29+%2F+%28+3+%2B+x+%29+=+.36+\"$
\n" ); document.write( " $\"+%28+2.16+%2B+.09%2A4+%29+%2F+%28+3+%2B+4+%29+=+.36+\"$
\n" ); document.write( " $\"++2.16+%2B+.36+=+.36%2A7+\"$
\n" ); document.write( " $\"+2.52+=+2.52+\"$
\n" ); document.write( "OK \n" ); document.write( "

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