First of all calm down and brake down the problem plan a is $25 a month while the other one is $40 you need to subtract to get $15 than divide $15 by $0.25 which you will get 60 but this is not the right answer because its asking you how many phone calls is the cost of plan b less than the cost of plan a so the answer is 59 calls.
You have to show more of the paper so i can calculate it. Sorry
