count the spaces on your graph until you reach the y axis then start over and count again till you count the same number that you it took you to reach the y axis... sounds kinda confusing.... but...
You change the value of y to -y. ex: (4,5) reflected over the x-axis is (4,-5)
by looking and controling it
no
Example: if you have a point with the coordinates (2,4), a reflection over the y-axis will result in the point with coordinates (-2,4).