The monthly cost (in dollars) of a long-distance phone plan is a linear function of the total calling time (in minutes). The monthly cost for 47 minutes of calls is $14.93 and the monthly cost for 90 minutes is $20.52. What is the monthly cost for 49 minutes of calls?

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step-by-step explanation:

since the sequence is geometric there is a common ratio r between consecutive terms, that is

r = 4 ÷ - 2 = - 2

r = - 8 ÷ 4 = - 2

r = 16 ÷ 8 = - 2

the next term - 13 must be incorrect as it should be - 32 for the sequence to be geometric.

the first 4 terms are therefore geometric with common ratio r = - 2

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!

8

step-by-step explanation: