How are the coordinates of a new point found if the point is reflected through the line y = x? How are the coordinates of the new point found if the point is reflected through the origin?

The point X (-3, 6) is a reflection of the point X' (3, -6). What are they reflected through?

Start with the point B (-1, -4). Reflect the point through the y-axis. What are the new coordinates of the point B'? Now reflect the point through the x-axis. What are the new coordinates of the point B''? What is the relationship between the original point B and B''? Can you describe this in terms of one reflection?