document.write( "Question 994496: How many grams of pure gold must be mixed with 40% gold alloy to produce 100 grams of 52% alloy? \n" ); document.write( "

Algebra.Com's Answer #613554 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+x+\"$ = grams of pure gold needed
\n" ); document.write( " $\"+.4%2A%28+100+-+x+%29+\"$ = grams of gold in 40% alloy
\n" ); document.write( "--------------------
\n" ); document.write( " $\"+%28+x+%2B+.4%2A%28+100+-+x+%29+%29+%2F+100+=+.52+\"$
\n" ); document.write( " $\"+x+%2B+40+-+.4x+=+.52%2A100+\"$
\n" ); document.write( " $\"+.6x+%2B+40+=+52+\"$
\n" ); document.write( " $\"+.6x+=+12+\"$
\n" ); document.write( " $\"+x+=+20+\"$
\n" ); document.write( "20 grams of pure gold are needed
\n" ); document.write( "-------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+x+%2B+.4%2A%28+100+-+x+%29+%29+%2F+100+=+.52+\"$
\n" ); document.write( " $\"+%28+20+%2B+.4%2A%28+100+-+20+%29+%29+%2F+100+=+.52+\"$
\n" ); document.write( " $\"+%28+20+%2B+.4%2A80+%29+%2F+100+=+.52+\"$
\n" ); document.write( " $\"+52+=+.52%2A100+\"$
\n" ); document.write( " $\"+52+=+52+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );