ANSWER: 3
<em><u>image at the bottom to help you visualize!</u></em>
First, Let's graph point A:
( The red point )
Now reflect point a across the X axis which is the horizontal line (to get point B):
( The blue point )
We see that --> in the point (5,-3), the y coordinate, (-3) changed to (3)
SO THE ANSWER WOULD BE:<u> 3</u>
Summary:
When you reflect a point across the x-axis, the x-coordinate remains the same, but the y-coordinate is transformed into its opposite (its sign is changed).
When you reflect a point across the y-axis, the y-coordinate remains the same, but the x-coordinate is transformed into its opposite (its sign is changed).
HOPE THIS HELPS!