Respuesta :

A (9,-4)

B (-9,4)

If it is across y axis then the x changes to the opposite
If it is across x axis then the y changes to the opposite
So basically when you reflect a point think of it as a mirror. So for example (5,3) reflected would be (-5,3) if you were reflecting it across the y axis. So the answer to a is (9,-4) and b is (-9,4)