Which expression is equivalent to this polynomial expression? (5xy2 + 3x2 – 7) + (3x2y2 - ry2 + 3y2 + 4)
A. 3x2y2 + 4xy2 + 3x2 + 3y2 – 3
B. 80272 + 2xy2 – 4y2 + 4
C. 97272 + 4ry2 – 3
D. 3.12y2 + 6ry2 + 6x2 + 3

An an average person has 6×10 by the power of two as many red blood cells as white blood cells a small sample of the blood has 7×10 by the power of three white blood cells about how many red blood cells are in the sample

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?

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?