So i'm doing flvs and i need to understand the difference between the answers to this question
pentagon pqrst and its reflection, pentagon p'q'r's't', are shown in the coordinate plane below:

what is the line of reflection between pentagons pqrst and p'q'r's't'?

x = 1
y = x
x = 0
y = 0

i know its line x but im not sure if its 1 or 0 or neither

I think I know what you are thinking and you are halfway on the right track. : ) You are probably looking at the x-axis right in between the pentagon and its reflection. This is the right line, but it is a y-line and not x. When we say a line is at x = 0, we mean that every point on that line has an x-value of 0, such as (0,1), (0,2), (0, 3) etc. Any line in the form x = 0 (or any other number) is a vertical line. Y-lines are the same way but they run horizontal like the line of reflection in this problem.        : )