respect to the y axis
the y axis is the vertical (up and down) line
so reflecting across the y axis means that yo mulply x by -1
(x,y) reflected across the y axis turns to (-x,y)
s
(-5,5) turns to (-(-5),5)=(5,5)
the point is (5,5)
it is 5 units up and 5 units to the right of the origin (intersection of x and y axises)