Anthony earns $35 per day during a 30 day period. he does not spend any more money during this 30 day period. he has a total of $500 on day 12. how much money did anthony already have at the beginning of the 30 day period?

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.