I need help on both of these provlems

Which graph corresponds to the function f(x) = x2 + 4x – 1?

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.

Math each whole number with a rational,exponential expression