Simplify 6 to the negative 3rd power over 6 to the 5th.

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?

Ineed to know the answer to this algebra question.

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.