Bella's cell phone cost 18$ per month plus 0.15$ for every minute she uses the phone. last month her bill was 29.25 how many minutes did she use her phone last month

Well, we know that 18 can't go into 29.25 more than once, so we would have to do 29.25 minus 18 which would be 11.25. Since it's plus .15, we have to divide 11.25 and .15.which would be 75. So that means she used 75 minutes last month.