First Plan
Monthly fee = $26
charge per min = $0.09
Second Plan
Monthly fee = $19
charge per min = $0.13
Solution
Let the number of minutes spent on calls in a specific month be x
The total cost spent using the first plan:
The total cost spent using the second plan:
If the cost from the first plan would be equal to that of the second plan:
Hence, the number of minutes of calls for which both plans would be equal is 175mins