Customers of a phone company can choose between two service plans for long distance calls. The first plan has a 26
monthly fee and charges an additional 0.08
for each minute of calls. The second plan has an 8
monthly fee and charges an additional 0.13
for each minute of calls. For how many minutes of calls will the costs of the two plans be equal?

Respuesta :

26+0.08x=8+0.13x
26-8=0.13x-0.08x
18=0.05x
x=18/0.05=360 min
--------------------------------------------------------
Define x :
--------------------------------------------------------
Let the number of minutes of call be x.

--------------------------------------------------------
First Plan :
--------------------------------------------------------
26 + 0.08x

--------------------------------------------------------
Second Plan :
--------------------------------------------------------
8 + 0.13x

--------------------------------------------------------
Find x so that the costs are the same :
--------------------------------------------------------
26 + 0.08x = 8 + 0.13x
0.13x = 0.08x = 26 - 8
0.05x = 18
x = 360 minutes

--------------------------------------------------------
Answer: 360 minutes of call.
--------------------------------------------------------