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43 votes
43 votes
Solving a decim For his long distance phone service, Justin pays a $3 monthly fee plus 11 cents per minute. Last month, Justin's long distance bill was $12.79. For how many minutes was Justin billed?​

User Vasily Vlasov
by
2.7k points

1 Answer

28 votes
28 votes

Answer:

89 minutes

Explanation:

Let

x = number of minutes

Total cost = fixed cost + variable cost

Total cost = $12.79

Fixed cost = $3

Variable cost = cost per minutes * number of minutes

= 0.11 * x

= 0.11x

Total cost = fixed cost + variable cost

12.79 = 3 + 0.11x

12.79 - 3 = 0.11x

9.79 = 0.11x

x = 9.79/0.11

x = 89

x = number of minutes = 89 minutes

User SolidSnake
by
3.5k points