Describe the end behavior of f(x)=-3x^38+7x^3-12x+13

(note i put the graph in so plz )the graph shows the amount of water that remains in a barrel after it begins to leak. the variable x represents the number of days that have passed since the barrel was filled, and y represents the number of gallons of water that remain in the barrel. what is the slope of the line

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

You are a clerk at convenience store. a customer owes 11.69 for a bag of potatoes chips. she gives you a five dollar bill. how much change should the customer receive?