Lynne took a taxicab from her office to the airport she had to pay a flat fee of 2.05 plus 0.90 the total cost was 5.65 how many miles was the takes trip

For this case we have that Lynne must pay:
 2.05 plus 0.90 per mile
 We have then that the equation that models the problem is:
 2.05 + 0.90x = 5.65
 Where,
 x: is the number of miles.
 Clearing x we have:
 0.90x = 5.65 - 2.06
 x = 3.59 / 0.90
 x = 4 miles
 
 the trip was:
 x = 4 miles