Question 392080: Sheridan's monthly phone bill includes a fixed charge, which is the same each month, and an additional charge for toll calls. One month the bill was $22, which included charges for 5 toll calls. The following month the bill was $26, which included charges for 7 toll calls. Find the fixed charge and the average charge per toll call.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Sheridan's monthly phone bill includes a fixed charge, which is the same each month, and an additional charge for toll calls.
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One month the bill was $22, which included charges for 5 toll calls.
f + 5t = 22
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The following month the bill was $26, which included charges for 7 toll calls.
f + 7t = 26
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Find the fixed charge and the average charge per toll call.
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Subtract 1st from 2nd equation and solve for "t":
2t = 4
t = $2 (cost of a toll call)
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Since f + 5t = 22
f + 5*2 = 22
f = $12 (fixed charge)
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Cheers,
Stan H.
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