Question 163538
While Mrs. Teacher was in China she decided to buy gifts for her wonderful students. Bracelets cost 12 Chinese dollars and necklaces cost 10 Chinese dollars. Mrs. Teacher bought a total of 55 bracelets and necklaces and spent a total of 620 Chinese dollars. How many bracelets and necklaces did the teacher buy. Show all work and explain your answer.
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Let b = no. of bracelets
Let n = no. of necklaces
:
total items equation
b + n = 55
:
Total cost equation
12b + 10n = 620
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Arrange the 1st equation so we can use it for substitution:
b + n = 55
n = 55-b; subtracted b from both sides
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Substitute (55-b) for n in the cost equation, find b
12b + 10(55-b) = 620
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12b = 550 - 10b = 620; multiplied what's inside the brackets
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12b - 10b = 620 - 550; subtracted 550 from both sides
:
2b = 70
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b = {{{70/2}}}; divided both sides by 2
b = 35 bracelets
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Find n
n = 55 -b
n = 55 - 35
n = 20 necklaces
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Check our solution in the cost equation
12b + 10n = 620
12(35) + 10(20) = 620
420 + 200 = 620; confirms our solutions