Multiply by 3 and add 1 help me plz :'(

The vet charges $45 for an office visit and $10 for each vaccination your dog needs. write an eaquation

Ill mark the brainliest if you me with the these three questions 7,8,9

Asales representative from a local radio station is trying to convince the owner of a small fitness club to advertise on her station. the representative says that if the owner begins advertising on the station today, the club's total number of members will grow exponentially each month. she uses the given expression to model the number of club members, in hundreds, after advertising for t months.