Answer:
7. 8200 miles
8. $350
Step-by-step explanation:
7. The first trip nets 3400 miles; the next four trips (for a total of five) net 1200 miles each, so the total for 5 round trips is ...
... 3400 + 4×1200 = 8200 . . . miles
8. The first month costs $100; the next 5 months (for a total of 6) cost $50 each, so the total for 6 months is ...
... $100 + 5×$50 = $350
