Riley is 3 years older than his sister. which of the following expressions shows the sum of their ages if s represents riley's sister's age?

2s + 3

Step-by-step explanation:

If we name s Riley's sister's age, the problem tells us that Riley is 3 years older than her so his age would be s + 3

Thus, the sum of their ages would be:

Riley's age + Riley's sister's age

(s + 3) + s = s + 3 + s = 2s + 3

Thus, the expression would be 2s + 3

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'.