Rationalize the denominator and simplify. 5/4-√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?

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)