document.write( "Question 445448: An art dealer sold 16 etchings for $630. He sold some of them at $35 each and the rest at $45 each. How many etchings did he sell at each price? \n" ); document.write( "

Algebra.Com's Answer #306842 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"a\"$ = number sold @ $35 each
\n" ); document.write( "Let $\"b\"$ = number sold @ $45 each
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+a+%2B+b+=+16+\"$
\n" ); document.write( "(2) $\"+35a+%2B+45b+=+630+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "Multiply both sides of (1) by $\"35\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+35a+%2B+45b+=+630+\"$
\n" ); document.write( "(1) $\"+-35a+-+35b+=+-560+\"$
\n" ); document.write( " $\"+10b+=+70+\"$
\n" ); document.write( " $\"+b+=+7+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+a+%2B+b+=+16+\"$
\n" ); document.write( "(1) $\"+a+%2B+7+=+16+\"$
\n" ); document.write( "(1) $\"+a+=+9+\"$
\n" ); document.write( "The number sold @ $35 each is 9
\n" ); document.write( "The number sold @ $45 each is 7 \n" ); document.write( "

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