Reduce to simplest form. -3/5 plus 1/3​

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?

Inez has a phone card. the graph shows the number of minutes that remain on her phone card a certain number of days.

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15