Question 1116452
staples sells boxes of pens ($10) and rubber bands($4).
Leona ordered a total of 24 cartons for $210. 
How many boxes of each did Leona order?
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Equations:
Quantity Eq:: p + b = 24 cartons
Value Eq::  10p + 4b = 210 dollars
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Modify for elimination of the "p" terms.
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10p + 10b = 240
10p + 4b = 210
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Subtract and solve for "b"::
6b = 30
b = 5 (# of boxes of bands)
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Solve for "p"::
p + 5 = 24
p = 19 (# of boxes of pens) 
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Cheers,
Stan H.
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