How can you use different representations of a relation to determine whether the relation is a function

Me! last question, and i'm stuck! write the algebraic expression that models the word phrase. the product of 2 divided by the number h and 8 more than the number k

Me with this one question, and i'll upvote the brainliest answer

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.