Looking at the diagram, A'B'C'D' is a reflection of ABCD across the x axis. We can see that the coordinate of B is (- 2, 6) and that of B' is (- 2 - 6). This conforms with the rule that when a figure is reflected across the x axis, the sign of the y coordinate changes.
For A'B'C'D' to A"B"C"D", we can see that the coordinate of B" is (6, - 2). This conforms with the rule of 90 degrees counterclocwise rotation which states that a coordinate, (x, y) becomes (- y, x). By applying this to B', it becomes (- - 6, - 2) = (6, - 2)
We can see that it corresponds, Therefore, the series of transformation are
ABCD to A'B'C'D' Reflection across the x axis
A'B'C'D' to A"B"C"D" 90 degrees counterclockwise rotation about the origin