SOLUTION: Commonwealth Edison company's charge for electricity in January 2010 is 9.44¢ (cents) per kilowatt-hour. In addition, each monthly bill contains a customer charge of $12.55. If las

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Question 1093222: Commonwealth Edison company's charge for electricity in January 2010 is 9.44¢ (cents) per kilowatt-hour. In addition, each monthly bill contains a customer charge of $12.55. If last year's bills ranged from a low of $76.27 to a high of $248.55, over what range did usage vary (in kilowatt-hours)?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = number of kw-hrs for low range of monthly bills
Let +b+ = number of kw-hrs for high range of monthly bills
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+9.44a+%2B+12.55+=+76.27+
+9.44a+=+63.72+
+a+=+6.75+
and
+9.44b+%2B+12.55+=+248.55+
+9.44b+=+236+
The range of usage is:
6.75 kw to 236 kw