Plz which relation is a function (choices are below)

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Scott’s bank account showed a balance of $750 on sunday. during the next five days, he made one deposit of $140 and numerous withdrawals of $180 each. let x represent the number of withdrawals that scott made. write an inequality that can be used to find the maximum number of withdrawals that scott could have made and maintain a balance of at least $100. do not use a dollar sign ($) in your response.

Which expression is equal to (f+g)(x)?