How do I solve for this question? I have tried some things so far all are wrong.

Question

A wireless carrier offers the following plans that a person is considering.

The Family Plan: $120 monthly fee, unlimited talk and text on up to 5 lines, and data charges of $45 for each device for up to 2 GB of data per device.

The Mobile Share Plan: $140 monthly fee for up to 10 devices, unlimited talk and text for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data.

Find the model of the total cost of the Mobile Share Plan in dollars. Use P for the number of devices that need data plans as part of their cost.

Answer 1

A wireless carrier offers the following plans that a person is considering.

The Family Plan: $120 monthly fee, unlimited talk and text on up to 5 lines, and data charges of $45 for each device for up to 2 GB of data per device.

The Mobile Share Plan: $140 monthly fee for up to 10 devices, unlimited talk and text for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data.

Find the model of the total cost of the Mobile Share Plan in dollars. Use P for the number of devices that need data plans as part of their cost.

Let T be the total cost of either of the two plans....so for the Family Plan T looks like this....

T = $120 + $45P where P<=5 and each device data use <=2G

now for the mobile plan the "model of the total cost..."

T= $140 + $35P where P<=10 and total shared data <=10G

.....Remember the question is only asking for the "model" ......Right?