According to this diagram, what is cos 28 degrees

What is the y-coordinate of the solution of the system of equations? [tex]y = 2x + 14 \\ - 4x - y = 4[/tex]y=

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 do i simply this radical expression?