SOLUTION: Roger bought hamburgers at a cost of $9 per dozen and bagels at a cost of $3 per dozen. He bought a total of 45 dozens and paid a total of $225. How many dozens of hamburgers and
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-> SOLUTION: Roger bought hamburgers at a cost of $9 per dozen and bagels at a cost of $3 per dozen. He bought a total of 45 dozens and paid a total of $225. How many dozens of hamburgers and
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Question 534284: Roger bought hamburgers at a cost of $9 per dozen and bagels at a cost of $3 per dozen. He bought a total of 45 dozens and paid a total of $225. How many dozens of hamburgers and how many dozens of bagels did he buy? Answer by oberobic(2304) (Show Source):
You can put this solution on YOUR website! h = number of dozens of hamburgers
9h = cost of the hamburgers
b = number of dozens of bagels
3b = cost of the bagels
.
h + b = 45
so
h = 45-b
and
b = 45-h
.
9h + 3b = 225
.
Multiply the first equation by 3.
.
3h + 3b = 135
9h + 3b = 225
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-6h = -90
.
h = -90/-6
h = 15
.
b = 45-15
b = 30
.
Answer: 15 dozen hamburgers and 30 dozen bagels.
.
Check the cost.
15*9 + 30*3 = 225
Correct.
.
Done.
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