Answer: Never(!) [assuming I understand/interpret the question properly]
Step-by-step explanation: The question wants to know how many months it will take for your neighbor's total cost be the same as yours, with three televisions. One has to interpret "total cost." I deem it to be the total accumulated costs, including installation. If you interpret it as the cost per month, then they charges are the same after the month the installation cast was paid. That's because the satellite provider charges per television, and 3*(13.32) is equal to the same 39.96/month charged by the cable provider. It the questions means total cumulative costs, the satellite customer will never exceed the cable customer's total bill, because of the installation fee ($75 for cable and free for satellite)