Simplify this equation 3m + 4 = -5

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?

Which of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?

If the value of cos330°is√3/2 then find cos 165°.