Answer: Frank was billed for 101 minutes
Explanation:
Let x represent the number of minutes for which Frank was billed.
For his long distance phone service, frank pays and $8 monthly fee plus 6 cents per minute. It means that the total amount that he would pay for x minutes in a month is
8 + 0.06x
Last month, Frank's long distance bill was $14.06. It means that
8 + 0.06x = 14.06
0.06x = 14.06 - 8
0.06x = 6.06
x = 6.06/0.06
x = 101 minutes