Explain how a solution found using substitution can be checked.

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 many $20 bills do you need to have to make $280

Explain how you divide powers with like bases.discuss why the bases have to be the same.how are these rules similar to the rules for multiplying powers with like bases.