Answer:
With 250 minutes of calls the cost of the two plans is the same
Step-by-step explanation:
We must write an equation to represent the cost of each call plan.
For the first plan
Monthly fee
$ 13
Cost per minute
$ 0.17
If we call x the number of call minutes then the equation representing the cost c for this plan is:
[tex]c = 13 + 0.17x[/tex]
For the second plan
monthly fee
$ 23
Cost per minute
$ 0.13
If we call x the number of call minutes then the equation representing the cost c for this plan is:
[tex]c = 23 + 0.13x[/tex]
To know when the cost of both plans are equal, we equate the two equations and solve for x.
[tex]13 + 0.17x = 23 + 0.13x\\\\0.17x -0.13x = 23-13\\\\0.04x = 10[/tex]
[tex]x = \frac{10}{0.04}[/tex]
[tex]x = 250\ minutes[/tex]
With 250 minutes of calls the cost of the two plans is the same: $55.5