Question

Pentagon PQRST and its reflection, pentagon P'Q'R'S'T', are shown in the coordinate plane below:

Answer 1

Yes, the answer is A. x=0. Another way to say "reflect across the y-axis" is to say "reflect across the line x=0" since the line created by graphing x=0 is the same as the y-axis. An image that is a reflection across the y-axis, or across the line x=0, will have opposite x-coordinates from the pre-image but identical y-coordinates. In other words, the x value points just changed signs from negative to positive values since it went through the rule (x, y) → (−x, y).

Answer 2

I have graphed the given coordinates of both pentagons. The reflection was across the y-axis where coordinates of Pentagon PQRST (-x,y) resulted to Pentagon P'Q'R'S'T' (x,y). The line of reflection between the pentagons was x = 0. Line of reflection is the midway between the pre-image and its reflection.