Is each pair equivalent or not ?

1 and 3 are true.

Step-by-step explanation:

For the first equation, you would add 2x to each side to result in the second equation.

For the third equation, you would divide by x on both sides, resulting in the second equation.

2. is not correct because the 3 is gone, and was "divided" from (x-4), but not the 15.

4. is not correct because of the extra x that is included in the second equation. That x makes the equations False.

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'.

what graph

step-by-step explanation: