Simplify the expression by combining like terms.
y + 9y + 5 - y - 3y + 2 - 4

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?

Oscar and julie ashton are celebrating their 15th anniversary by having a reception hall. they have budgeted $4,500 for their reception. if the reception hall charges a $90 cleanup fee plus & 36 per person, find the greatest number of people that they may invite and still stay within their budget.

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?