document.write( "Question 151577: A vending machine will accept nickels and dimes only. The attendant checks the machine and finds 42 coins whose value is $3.40. How many coins of each type were there? \n" ); document.write( "

Algebra.Com's Answer #111414 by jojo14344(1513) $\"\"$ $\"About$

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Let $\"x=nickels\"$
\n" ); document.write( " $\"y=dimes\"$
\n" ); document.write( "so, $\"x%2By=42\"$ , right? ----------------> eqn 1
\n" ); document.write( "Also, $\"0.05x%2B0.10y=3.40\"$ ------------> eqn 2
\n" ); document.write( "in eqn we get, $\"y=42-x\"$ , substitute in eqn 2 we have,
\n" ); document.write( " $\"0.05x%2B0.10%2842-x%29=3.40\"$
\n" ); document.write( " $\"0.05x%2B4.2-0.10x=3.40\"$
\n" ); document.write( " $\"4.20-3.40=0.10x-0.05x\"$
\n" ); document.write( " $\"0.80%2F0.05=cross%280.05%29x%2Fcross%280.05%29\"$ -----------> $\"x=16\"$ , # of dimes
\n" ); document.write( "For # of nickels go back eqn 1:
\n" ); document.write( " $\"16%2By=42\"$ , $\"y=42-16=26\"$ , # of nickels
\n" ); document.write( "In doubt? Go back eqn 2;
\n" ); document.write( " $\"0.05%2816%29%2B0.10%2826%29=3.40\"$
\n" ); document.write( " $\"0.80%2B2.60=3.40\"$
\n" ); document.write( " $\"3.40=3.40\"$
\n" ); document.write( "Thank you,
\n" ); document.write( "Jojo \n" ); document.write( "

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