Question 935846: pat bought 45 stamps , some for 10c and some for 18c. If he spent $6.66 altogether, how many 10c stamps did he buy? Found 2 solutions by TimothyLamb, josmiceli:Answer by TimothyLamb(4379) (Show Source):
You can put this solution on YOUR website! x = number of 10 cent stamps
y = number of 18 cent stamps
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x + y = 45
10x + 18y = 666
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put the system of linear equations into standard form
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x + y = 45
10x + 18y = 666
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solution:
x = number of 10 cent stamps = 18
y = number of 18 cent stamps = 27
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You can put this solution on YOUR website! Let = number of 10 cent stamps
Let = number of 18 cent stamps
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(1)
(2) ( in cents )
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(2)
Multiply both sides of (1) by and
subtract (1) from (2)
(2)
(1)
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and
(1)
(1)
(1)
He bought 18 10c stamps
