The charges for a telephone call are $0.45 for the first 3 minutes and $0.09 for each additional minute or part of a minute. Represent the cost of a telephone call that lasts m minutes when m is greater than 3.
0.45(3)+0.09(m-3)
To represent the cost of a telephone call that lasts m minutes when m is greater than 3, we need to consider the initial 3 minutes separately and then calculate the cost for the remaining minutes.
For the first 3 minutes, the charge is $0.45. So, for these initial 3 minutes, the cost would be $0.45.
To calculate the cost for the additional minutes, we need to subtract the first 3 minutes from the total duration m. This will give us the number of additional minutes, represented as (m - 3). Since each additional minute or part of a minute costs $0.09, we can multiply (m - 3) by $0.09 to get the cost for the additional minutes.
Therefore, the total cost C of a telephone call that lasts m minutes when m is greater than 3 can be represented as:
C = $0.45 + ($0.09 × (m - 3))
Alternatively, we can simplify the equation as:
C = $0.45 + $0.09(m - 3)
This equation provides a representation of the cost of a telephone call that lasts m minutes in terms of the variable m.