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Chiomatn93
The credit remaining on a phone card (in dollars) is a linear function of the total calling time made with the card (in minutes). The remaining credit after33 minutes of calls is $20.05 , and the remaining credit after 67 minutes of calls is $14.95 . What is the remaining credit after 76 minutes of calls?
hmm so lets make x=# of minutes and y= remaining credit so we would get points (33,20.05) and (67,14.95) now lets find slope |dw:1336882216929:dw|
now put slope and one of the points into point slope formula |dw:1336882289521:dw|
|dw:1336882305193:dw|
ok so whats the answeR?
now the question is asking for the remaining balance after 76 minutes so sub in 76 for x to find y |dw:1336882417666:dw|
if you have any questions feel free :/