babystar16
if 8 pens and 7 pencils cost $3.37 while 5 pens and 11 pencils cost $3.10, how much does each pen and pencil cost?



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MathLegend
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@babystar16 do you want me to show you how to solve?

babystar16
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plzzzzzzzzzzzzzzz

MathLegend
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So we can setup system of linear equation.

MathLegend
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P = Pens
C = Pencils

MathLegend
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8p+7c=3.37
5p+11c=3.10

MathLegend
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@babystar16 can't we multiply both of the 'p' variables to get a common number? Lets multiply the 8p times 5. Then the 5p times 8.

MathLegend
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40p35c=16.85
40p+88c=24.80
 (Now, we add...)
53c = 7.95
c = .15

MathLegend
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@babystar16 do you understand this?

MathLegend
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Now, just plug back in .15 for c in the original equation.

MathLegend
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5p+11(.15)=3.10
5p + 1.65 = 3.10
5p = 1.45
p = .29

MathLegend
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Pens were .29 cent
Pencils were .15 cent

babystar16
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thank u

babystar16
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thank u for helping me understand it