The answer is it is yes, it is sometimes true, y can =0
You can consider the triangle (as on in the picture) and apply to it composition of two transformations:
1. reflection about the line y=x to form ΔA'B'C' and translation 1 unit right and 5 units up to form ΔA''B''C'';
2. translation 1 unit right and 5 units up to form ΔA'B'C' and reflection about the line y=x to form ΔA''B''C''.
You can see that results are different.
On added picture blue colour responds to composition of transformations 1 and red colour to composition of transformations 2.
A scale displaying digits...
For the first one it's A.
Third one is, True
The last one is C,
This is all I know I hope I helped, sorry I couldn't with the others :(