It took 1.25 hours to install the DVD system.
Work Step by Step
Let X represent the number of hours it took to install the DVD system. 60 dollars an hour for installation means 60X An additional 379 dollars for the DVD player makes the expression 379 + 60X Robin paid a 454 bill for a car DVD system. So, we obtain: 379 + 60X = 454 Subtract 379 from both sides 60X = 75 Divide both sides by 60 X = 1.25