Please explain what this means! (no math needs to be done as I got the answers but I don't understand the explanation...)

you can imagine this as a venn diagram. the "or" event would consist of everything in both sides and the middle of the venn diagram because you can choose form either event x or event y.

the "and" event would consist of everything in the middle of the venn diagram because you choice must be a part of both event x and event y.

the complement of an event is just everything that is not included in the event. for example, in a coin flip, the complement of heads is tails. in a dice roll, the complement of {1,2} is {3,4,5,6}

so if you come across these just think "either or" or "both and." and remember that the complement is everything excluding what is listed.

i apologize if this does not help, im not that great at explaining things

the answer is (4,3)

since the rule for r0, 90º is (-y,x) and it was already applied to form the image, all you have to do is reverse the answer using this formula.