I’m stuck on this question. i’m very confused.

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

Find the difference (8ab+a+2) - (3ab+6)

Which expression is equal to (f+g)(x)?