document.write( "Question 581167: A dollar was changed into 16 coins consisting of just 5 cent and 10 cent coins. How many coins of each kind were in the change? \n" ); document.write( "

Algebra.Com's Answer #371479 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+d+\"$ = number of 10 cent coins
\n" ); document.write( "Let $\"+n+\"$ = number of 5 cent coins
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+d+%2B+n+=+16+\"$
\n" ); document.write( "(2) $\"+10d+%2B+5n+=+100+\"$ ( in cents )
\n" ); document.write( "--------------------------
\n" ); document.write( "Multiply both sides of (1) by $\"+5+\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+10d+%2B+5n+=+100+\"$
\n" ); document.write( "(1) $\"+-5d+-+5n+=+-80+\"$
\n" ); document.write( " $\"+5d+=+20+\"$
\n" ); document.write( " $\"+d+=+4+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+d+%2B+n+=+16+\"$
\n" ); document.write( "(1) $\"+4+%2B+n+=+16+\"$
\n" ); document.write( "(1) $\"+n+=+12+\"$
\n" ); document.write( "The number of 10 cent coins is 4
\n" ); document.write( "The number of 5 cent coins is 12
\n" ); document.write( " \n" ); document.write( "

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