So first just list the points which is pretty easy, then to make it easy flip your paper, or phone, 180° which would just be upside down. Now pretending that the graph is the right side up count the point. (Example: A (-4, 2) to now be A’ (4, -2). From these points you can see the rule which would be (-x, -y). If you don’t want to count all the points a second time you can apply this rule to the points. (Another example: (2, 3) -> (-2, -3))
For the 90°, you would also flip your paper again and make sure it’s the right way, clockwise in this case, so the point A would be (-4, 2) -> (2, 4). This rule would be (y, -x). Then you would find the rest of your points.
I hope this helps even though it was a pretty long explanation
