#### Answer

The limousine was used for 4.5 hours.

#### Work Step by Step

Let X represent the number of hours that the limousine was used.
A 80 dollars for each hour of use means 80X
A 150 dollar fee for the service makes the expression 150 + 80X
The bill from the limousine company was 510.
So: 150 + 80X = 510
Subtract 150 from both sides
80X = 360
Divide both sides by 80
X = 4.5