document.write( "Question 1025511: A contractor mixes concrete from bags of pre-mix for small jobs. How many bags with 3% cement should he mix with 10 bags of 18.2% cement to produce a mix containing 11% cement? \n" ); document.write( "

Algebra.Com's Answer #640806 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+x+\"$ = bags of 3% cement needed
\n" ); document.write( " $\"+.182%2A10+=+1.82+\"$ bags of pure cement in 18.2% mix
\n" ); document.write( "--------------------
\n" ); document.write( " $\"+%28+.03x+%2B+1.82+%29+%2F+%28+x+%2B+10+%29+=+.11+\"$
\n" ); document.write( " $\"+.03x+%2B+1.82+=+.11%2A%28+x+%2B+10+%29+\"$
\n" ); document.write( " $\"+.03x+%2B+1.82+=+.11x+%2B+1.1+\"$
\n" ); document.write( " $\"+.08x+=+.72+\"$
\n" ); document.write( " $\"+x+=+9+\"$
\n" ); document.write( "9 bags of 3% cement are needed
\n" ); document.write( "-------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+.03x+%2B+1.82+%29+%2F+%28+x+%2B+10+%29+=+.11+\"$
\n" ); document.write( " $\"+%28+.03%2A9+%2B+1.82+%29+%2F+%28+9+%2B+10+%29+=+.11+\"$
\n" ); document.write( " $\"+%28+.27+%2B+1.82+%29+%2F+19+=+.11+\"$
\n" ); document.write( " $\"+.27+%2B+1.82+=+2.09+\"$
\n" ); document.write( " $\"+2.09+=+2.09+\"$
\n" ); document.write( "OK \n" ); document.write( "

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