Answer:
D. f(x) = 0.40x + 40
Step-by-step explanation:
The given problem involves a fixed initial fee of $40 and an additional charge of $0.40 per minute. This can be represented as a linear function where the output (the total cost) depends on the input (the number of minutes).
Initial Fee: The plan charges an initial fee of $40 regardless of how many minutes are used. This initial fee is like a fixed cost that you pay upfront, regardless of your usage.
Per Minute Charge: In addition to the initial fee, there's an additional charge of $0.40 per minute. This means for each minute you use, you'll be charged $0.40 extra.
Now, to represent this situation mathematically, we can use a function where:
• x represents the number of minutes used.
• f(x) represents the total cost.
The total cost (f(x)) is composed of two parts:
1. The fixed initial fee of $40.
2. The variable charge, which is $0.40 per minute multiplied by the number of minutes used (0.40x).
So, the function f(x)can be expressed as the sum of these two parts:
f(x) = Initial Fee + Per Minute Charge
f(x) = 40 + 0.40x
Therefore, the correct function equation representing this problem is:
f(x) = 0.40x + 40