A cell phone plan charges $1.25 for the first 400 minutes and $0.25 for each additional minute, x. W

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A cell phone plan charges $1.25 for the first 400 minutes and $0.25 for each additional minute, x. Which represents the cost of the cell phone plan?

Let C(x) be the cost function where x is the number of minutes we have:
C(x) = 1.25(min(400, x)) + 0.25(Max(0, 400 - x))