The average (arithmetic mean) of a - 5 and a is x, and the average of a and a + 9 is y. What is the average of x and y? a + 1
B) a +2
C) 2a + 1
D) 2a + 2

Use the distributive property -7(-2x+u-2)

4. jake needs to score in the top 10% in order to earn a physical fitness certificate. the class mean is 78 and the standard deviation is 5.5. what raw score does he need? z value for top 10% =1.282 how do i get the z value? what is the equation for this? raw score =mean+z*sd = 78+1.282*5.5 = 85.051

The area (in square feet) of an x-foot-wide sidewalk can be modeled by y=-0.002x^2+0.006x. what is the width of the sidewalk to the nearest foot?