Question

A basic cellular package costs $30/month for 60 minutes of calling with an additional charge of $0.40/minute beyond that time. The cost function C (2) for using x minutes would be • If you used 60 minutes or less, i.e. if if x < 60, then C (x) = 30 (the base charge). If you used more than 60 minutes, i.e. (x – 60 minutes more than the plan came with, you would pay an additional $0.40 for each of those (x – 60 minutes. Your total bill would be C (x) = 30 + 0.40 (x – 60). If you want to keep your bill at $50 or lower for the month, what is the maximum number of calling minutes you can use? minutes. The maximum calling minutes you can use is ? Number​

Answer 1

Answer:

The maximum number of minutes to keep the cost at $50 or less is 110 minutes

Step-by-step explanation:

Given

$C(x) = 30$ ---- $x < 60$

$C(x) = 30 + 0.40(x - 60)$ --- $x \ge 60$

Required

$C(x) = 50$ ---- find x

We have:

$C(x) = 30 + 0.40(x - 60)$

Substitute 50 for C(x)

$50 = 30 + 0.40(x - 60)$

Subtract 30 from both sides

$20 = 0.40(x - 60)$

Divide both sides by 0.40

$50 = x - 60$

Add 60 to both sides

$110 = x$

$x =110$