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Define x :
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Let x be the number of 5 cents she has.
5 cents = x
10 cents = 2x
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Find value in term of x :
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5 cents = $0.05x
10 cents = 0.10(2x) = 0.2x
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Construct Equation :
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The total amount is $3.50
⇒ 0.05x + 0.2x = 3.50
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Solve x :
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0.05x + 0.2x = 3.50
0.25x = 3.5
x = 14
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Find the number of coins :
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5 cents = x = 14
10 cents = 2x = 2(14) = 28
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Answer: She has 14 5-cents.
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