document.write( "Question 126875: How many pounds of a 12% aluminum alloy must be mixed with 400 pounds of a 25% aluminum alloy to make a 17% aluminum alloy? \n" ); document.write( "

Algebra.Com's Answer #92945 by josmiceli(19441) $\"\"$ $\"About$

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In words:
\n" ); document.write( "(pounds of aluminum in 12% alloy) + (pounds of aluminum in 25% alloy)
\n" ); document.write( "divided by (total pounds of mixture) = 17%
\n" ); document.write( "Let $\"a\"$ = pounds of 12% alloy needed
\n" ); document.write( "Let $\"b\"$ = pounds of 25% alloy needed
\n" ); document.write( " $\"%28.12a+%2B+.25b%29+%2F+%28a+%2B+b%29+=+.17\"$
\n" ); document.write( " $\"b+=+400\"$
\n" ); document.write( " $\"%28.12a+%2B+.25%2A400%29+%2F+%28a+%2B+400%29+=+.17\"$
\n" ); document.write( " $\"%28.12a+%2B+100%29+%2F+%28a+%2B+400%29+=+.17\"$
\n" ); document.write( " $\".12a+%2B+100+=+.17%28a+%2B+400%29\"$
\n" ); document.write( " $\".12a+%2B+100+=+.17a+%2B+68\"$
\n" ); document.write( " $\".05a+=+32\"$
\n" ); document.write( " $\"a+=+640\"$
\n" ); document.write( "640 pounds of 12% alloy must be used
\n" ); document.write( "check answer
\n" ); document.write( " $\"%28.12a+%2B+.25b%29+%2F+%28a+%2B+b%29+=+.17\"$
\n" ); document.write( " $\"%28.12%2A640+%2B+.25%2A400%29+%2F+1040+=+.17\"$
\n" ); document.write( " $\"%2876.8+%2B+100%29+%2F+1040+=+.17\"$
\n" ); document.write( " $\"176.8+=+1040%2A.17\"$
\n" ); document.write( " $\"176.8+=+176.8\"$
\n" ); document.write( "OK \n" ); document.write( "

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