SOLUTION: a customer walks into a post office to purchase stamps she purchases 46 stamps some stamps are 49 cents some are 33 cents how many 49 cent stamps and how many 33 cent stamps did sh

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: a customer walks into a post office to purchase stamps she purchases 46 stamps some stamps are 49 cents some are 33 cents how many 49 cent stamps and how many 33 cent stamps did sh      Log On


   



Question 1056539: a customer walks into a post office to purchase stamps she purchases 46 stamps some stamps are 49 cents some are 33 cents how many 49 cent stamps and how many 33 cent stamps did she purchase if the total cost was $19.34
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = thr number of 33 cent stamps she bought
Let +b+ = the number of 49 cent stamps she bought
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(1) +a+%2B+b+=+46+
(2) +33a+%2B+49b+=+1934+ ( in cents )
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Multiply both sides of (1) by +33+
and subtract (1) from (2)
(2) +33a+%2B+49b+=+1934+
(1) +-33a+-+33b+=+-1518+
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+16b+=+416+
+b+=+26+
and
(1) +a+%2B+26+=+46+
(1) +a+=+20+
OK
She bought 20 of the 33 cents stamps
She bought 26 of the 49 cent stamps
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check:
(2) +33a+%2B+49b+=+1934+
(2) +33%2A20+%2B+49%2A26+=+1934+
(2) +660+%2B+1274+=+1934+
(2) +1934+=+1934+
OK