Find all real numbers for which the rational expression is undefined. (Enter your answers as a comma-separated list. If no values make the expression undefined, enter NONE.) 6x − 19
x2 − 9

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

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?

If the altitude is drawn to the hypotenuse of a right triangle, then the two triangles formed are similar to the original triangle and to each other. which set of triangles shows the similar triangles created by the altitude in the diagram?