Help me on this please do it fast please

Plz need answer now will mark which situations represent linear functions? check all that apply. a)the temperature rises and falls over the course of a day. temperature is a function of time. b)a baseball is hit into the outfield. the height of the ball is a function of time. c)a car goes 55 mph on the highway. distance is a function of time. d)a child grew 2 inches this year and 1 inch last year. height is a function of time. e)a movie director makes 2 movies per year. the number of movies is a function of the years.

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.