274.6 = 2.746 x 10n n =

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

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?

How do i do this activity, is appreciated