What does reflecting in the y access mean

If you mean axis then the answer is that the coordinate on the y axis stays the same but the coordinate on the x axis is the opposite.

For example, if the number on the y axis on quadrant 1 is 4 then if it's reflected onto quadrant two, the number will stay the same but if the number on the x axis is 4 then if it's reflected onto quadrant two, the number will be -4

the answer is (-4,-4)

hope this ! : d