When simplifying an exponential expression what happens to an exponent when it is moved from the numerator to the denominator or the denominator to the numerator?

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

What is negative 3/9 times negative 2/8 ?