Answer:
179 minutes
Explanation:
From the information given, you know that the total cost of the long distance service is equal to 7 plus the result of multiplying 0.7 for the number of minutes:
Total cost=7+0.07x, where x is the amount of minutes.
Now, you can replace the total cost with 19.53 that is the amount Ali was billed and solve for x:
19.53=7+0.07x
19.53-7=0.07x
12.53=0.07x
x=12.53/0.07
x=179
According to this, the answer is that Ali was billed for 179 minutes.