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kodGreya [7K]
3 years ago
15

adam spent 13.10 on supplies for school. book covers cost 1.50 and boxes of mechanical pencils were each 2.80. if he bought seve

n items total, then how many of each did he buy
Mathematics
1 answer:
Flauer [41]3 years ago
7 0
<h3>Answer:</h3>

5 book covers and 2 boxes of pencils

<h3>Step-by-step explanation:</h3>

If all 7 were book covers, the cost would be 10.50. The cost is 2.60 more than that. Each box of mechanical pencils costs 1.30 more than a book cover, so there must be 2.60/1.30 = 2 boxes of mechanical pencils (and 5 book covers).

_____

If you want an equation, let p represent the number of pencil boxes. Then 7-p is the number of book covers.

... 1.50(7-p) +2.80p = 13.10

... 1.30p = 13.10 -10.50 . . . . . subtract 10.50, collect terms

... p = 2.60/1.30 = 2 . . . . pencil boxes

... 7-2 = 5 . . . . . book covers

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