Find the center and the radius of the circle with the equation: x^2-2x y^2 4y 1=0
a. center: (1, 2) radius: 4
b. center: (2, -4) radius: 1
c. center: (1, 2) radius: 2
d. center: (1, -2) radius: 2

Suppose there are 10 five and six-year-old attending a birthday party. when a 30 year old mother walks into the room with an infant in her arms, what happens to the mean age in the room? what happens to the standard deviation of ages in the room? a. the mean and standard deviation of both change. b. the meaning will change, but the standard deviation will stay approximately the same. c. i mean will stay approximately the same, but the standard deviation will change. d. the mean and standard deviation will both stay approximately the same.

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Problem fathi wants to print out a pdf document that is 48 pages long. to save paper, he decides to print on both sides of each sheet and to print two pages on each side of the sheet. how many sheets of paper will he need?