. Paul signs up for a new cell phone plan. He is offered a discount for the first five months.
After this period, his rate increases by $8.50 per month.
His total cost at the end of the year is $245.50.
Paul wrote the following equation to represent his plan.
5x + 7(x + 8.50) = 245.50

Part A:
How much, in total, will Paul pay during the five discounted months of his plan?

Part B:
Explain and justify how you arrived at your answer.