If you evaluate (-2) 15 will the answer be positive or negative? Determine a general rule for the sign of the answer when a negative base is raised to an exponent that is a positive integer.

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

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?

What is the number 321,000,000 in scientific notation? also what is the number? ?