Which expression is equivalent to 2x^2+2x-4 over 2x^2-4x+2

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 value of f(x) = 2.2 for f(-2)?

Prove that (x-2)is factor of p (x)=2x³-3x²-17x+30