Assignment:
Harry and Irene decided to take a road trip. The first 45 miles of the drive is pretty easy, while the last 76 miles of the drive is filled with curves. The drove at an average of 7 miles per hour faster for the first 45 miles of the trip. The entire trip took 4 hours. How fast were Harry and Irene driving for the first 45 miles of the trip?
Provide complete and step by step solution for the question and show calculations and use formulas.