This is correct. The x-axis and the y-axis cross each other under a 90 degree angle. This gives us 4 quadrants with different values. The first quadrant is the upper-right (+,+), the second quadrant is, going counter-clockwise, the upper left (-,+), the third quadrant is the lower left (-,-), and the last, fourth one is the lower right (-,+). Positive values on the x-axis are on the right side of the meeting point, and the negative values are on the other side. The positive values on the y-axis are on the upper part. So, if the point is first with two positive values, it means that it is in the 1st quadrant. Moving it across the x-axis would take it in the same position but down, in the 4th quadrant (-,+), and then reflecting it across the y-axis would move it in the same place but left, like in a mirror, and it would place it in the 4th quadrant with two negative values, or -x, -y like the statement.
