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Find hour rate for 7 hours:
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Hourly charge = $3
Hourly charges for 7 hours = 3 x 7 = $21
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Find fixed charge :
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$33-21 = $12
There is a $12 fixed rental charge.
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Form Equation:
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Let the number of hours be x.
Total cost = 12 + 3x
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Answer: Total cost = 12+ 3x
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