The ratio of dogs to cats at the pet store is 1:3 if there are 6 more cats than dogs, how many dogs are at the pet store

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.