Joseph took skydiving lessons. the skydiving shack charges $45 per hour for lessons. joseph also gave his skydiving instructor a tip of $20. (a) define the unknown in the scenario and assign it a letter or symbol. the unknown is how long he took the lessons for. the letter i choose is x (b) write an expression to represent the amount of money that joseph paid for his skydiving adventure. (score for question 3: of 5 points)