Ayudenme con estas 4 operaciones por favor, doy 24 puntos : ( lo necesito urgente

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.

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 5x^2 + 10x