document.write( "Question 181596This question is from textbook algebra structure & method book1
\n" ); document.write( ": Kyle spent $4.95 to buy 15 stamps in .25 and.40 denominations. How many of each kind of stamp did he buy? \n" ); document.write( "

Algebra.Com's Answer #136213 by josmiceli(19441) $\"\"$ $\"About$

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$\"a\"$ = number of .25 stamps
\n" ); document.write( " $\"b\"$ = number of .40 stamps
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"a+%2B+b+=+15\"$
\n" ); document.write( "(2) $\".25a+%2B+.4b+=+4.95\"$
\n" ); document.write( "Multiply both sides of (1) by $\".4\"$
\n" ); document.write( "and subtract (2) from (1)
\n" ); document.write( "(1) $\".4a+.4b+=+6\"$
\n" ); document.write( "(2) $\"-.25a+-+.4b+=+-4.95\"$
\n" ); document.write( " $\".15a+=+1.05\"$
\n" ); document.write( " $\"a+=+7\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"a+%2B+b+=+15\"$
\n" ); document.write( " $\"7+%2B+b+=+15\"$
\n" ); document.write( " $\"b+=+8\"$
\n" ); document.write( "He bought $\"7\"$ .25 stamps and $\"8\"$ .40 stamps
\n" ); document.write( "check:
\n" ); document.write( "(2) $\".25a+%2B+.4b+=+4.95\"$
\n" ); document.write( "(2) $\".25%2A7+%2B+.4%2A8+=+4.95\"$
\n" ); document.write( " $\"1.75+%2B+3.2+=+4.95\"$
\n" ); document.write( " $\"4.95+=+4.95\"$
\n" ); document.write( "OK \n" ); document.write( "

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