1a is OK - it's a translation through -6 in the x-direction and 3 in the y-direction.
1b is OK - if r y = x represents a reflection in y = x.
1c is OK - if R o,90 means a rotation centre O, through 90 degrees anticlockwise.
I think 2a is OK - provided D2 represents an enlargement with scale factor 2, centre O. (But I don't see why the letter D is used.)
2b doesn't seem to make sense to me. What does r origin mean?
2c is OK - if r x-axis is a reflection in the x-axis.
So all your answers make sense except the second part of question 2. Do you need to look at that one again?