My methods aren’t working, how do you solve this

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?

You got a job selling magazines door-to-door. you are paid $100 per day plus $1.50 for each magazine you sell. which recursive formula models this situation?

Simplify. 3(4+4x) (type your answer in with no spaces)