Reagan surveyed a number of her classmates about what time they usually go to bed. of the fifteen classmates she asked, three said 9 p. m. what percent of the students is this?

20%

Step-by-step explanation:

We can say that 3/15 students usually go to bed at 9 P.M. We can set up a proportion to solve this problem.

3/15=x/100

We cross multiply to find x

15x=300

Divide both sides by 15

x=20

So 20% of the classmates usually sleep at 9 P.M.

(w – 2.5)(w + 2.5)

(–4v – 9)(–4v + 9)

step-by-step explanation:

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.