Help please? i dont wanna fail qwq

Which expressions are equivalent to -6 + 3m

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Reagan lives five miles farther from school than vanessa lives. write an expression to describe how far reagan lives from school