SOLUTION: Kyle spent $4.95 to buy 15 stamps in .25 and.40 denominations. How many of each kind of stamp did he buy?

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

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
a= number of .25 stamps
b = number of .40 stamps
given:
(1) a+%2B+b+=+15
(2) .25a+%2B+.4b+=+4.95
Multiply both sides of (1) by .4
and subtract (2) from (1)
(1) .4a+.4b+=+6
(2) -.25a+-+.4b+=+-4.95
.15a+=+1.05
a+=+7
and, since
(1) a+%2B+b+=+15
7+%2B+b+=+15
b+=+8
He bought 7 .25 stamps and 8 .40 stamps
check:
(2) .25a+%2B+.4b+=+4.95
(2) .25%2A7+%2B+.4%2A8+=+4.95
1.75+%2B+3.2+=+4.95
4.95+=+4.95
OK