document.write( "Question 519443:
\n" ); document.write( "
\n" ); document.write( "...A coffee merchant combines coffee costing $6.00 per pound with coffee costing $4.50 per pound. How many pounds of each should be used to make 30 lb of a blend costing $5.30 per pound?
\n" ); document.write( "$6.00/lb coffee 1 lb
\n" ); document.write( "$4.50/lb coffee 2 lb \n" ); document.write( "

Algebra.Com's Answer #345598 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"a\"$ = pounds of $6 coffee needed
\n" ); document.write( "Let $\"b\"$ = pounds of $4.50 coffee needed
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+a+%2B+b+=+30+\"$
\n" ); document.write( "(2) $\"+%2860a+%2B+45b%29+%2F+30+=+53+\"$ ( in dimes)
\n" ); document.write( "-------------------------
\n" ); document.write( "(2) $\"+60a+%2B+45b+=+1590+\"$
\n" ); document.write( "(2) $\"+4a+%2B+3b+=+106+\"$
\n" ); document.write( "Multiply both sides of (1) by $\"3\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+4a+%2B+3b+=+106+\"$
\n" ); document.write( "(1) $\"+-3a+-+3b+=+-90+\"$
\n" ); document.write( " $\"+a+=+16+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+a+%2B+b+=+30+\"$
\n" ); document.write( "(1) $\"+b+=+30+-+16+\"$
\n" ); document.write( "(1) $\"+b+=+14+\"$
\n" ); document.write( "16 pounds of $6 coffee are needed
\n" ); document.write( "14 pounds of $4.50 coffee are needed
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+%2860%2A16+%2B+45%2A14%29+%2F+30+=+53+\"$
\n" ); document.write( "(2) $\"+%28960+%2B+630%29+%2F+30+=+53+\"$
\n" ); document.write( "(2) $\"+1590+=+53%2A30+\"$
\n" ); document.write( "(2) $\"+1590+=+1590+\"$
\n" ); document.write( "OK \n" ); document.write( "

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