What equation goes along with this problem?

To figure this out, let's look at some important numbers. 60.50, 45, and 0.25. Those are the numbers we'll be using in our equation. First, we need to figure out how much money Dante spent on the flat cost, which was $45.
60.50 - 45 = 15.50
Now, to figure out how many texts Dante sent, all we have to do is divide the $15.50 we got from the above equation by the $0.25 it costed him for each text.
15.50 / 0.25 = 62
There's our answer. Dante sent 62 texts last month.
The full equation for this problem would look something like this:
(60.50-45) / 0.25
Hope this answer helped you out. :)