Final answer:
To find the reflected points A' and B' in the line y = -x, apply the reflection rules to transform the original coordinates. Point A(2, -1) becomes A'(1, -2), and point B(2, -2) becomes B'(2, -2) after reflection.
Step-by-step explanation:
The question asks for new coordinates of points A and B after being reflected in the line y = -x on the Cartesian plane. By applying the rules for reflection, which stipulate that if the point (a, b) is reflected in the line y = -x, then its image point is (-b, -a), we can find the transformed points A'(2, -1) and B'(2, -2).
The new coordinates for point A' after reflection will be (-(-1), -2) which simplifies to (1, -2). Similarly, the coordinates for point B' after reflection will be (-(-2), -2) which gives us (2, -2).