All this is, is plugging in numbers. Then taking the square root of it. The first one would be the square root of 6 squared - 4(5)(-3). That would simplify to the square root of 36+60. Then add the numbers to get the square root of 96. The square root of 96 is about 9.798. I hope that helped. If you still need help with the second one or with the rest of the formula (if there is one) just ask!
Data from random samples will not always include the same values. Values are chosen randomly and they may or may not be the same. So means will vary among samples.
