Answer: her call lasted for 44 minutes
Explanation:
Linda purchase a prepaid phone card for $30. This means that the credit on her card is $30.
Long distance calls cost $0.17 each. Linda use her card only to make a long distance call. Assuming she made a total of x minutes of long distance calls, the cost would be $0.17x. The amount remaining on her card will be
30 - 0.17x
if the remaining credit on her card is $22.52, the number of minutes,x that the call lasted will be
22.52 = 30 - 0.17x
0.17x = 30 - 22.52
0.17x = 7.48
x = 7.48/0.17 = 44