Intr-o clasa snt 35 de elevi .nr fete este egal cu 75 la suta din nr baietilor .aflati nr baietilor

Salut!

b=baiat

f=fata

In clasa sunt 35 elevi.

75/100 x b=f

3b/4=f

3b=4f

b+f=35

3b+3f=105

7f=105

f=15

b=35-15

b=20

Succes!

goog may have it for you

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'.