(5,-7) to (-5,7) Here both abscissa and ordinate are changing their signs. This happens when a point is reflected in origin.
(4,-8) to (-4,-8) Here, only sign of abscissa is changed. This is possible when a point is reflected in y-axis.
(4,2) to (4,-2) Here, only sign of ordinate is changed. This implies point is reflected in x-axis.
(0,6) to (0,6) Here, image of a point is the point itself i.e it is invariant point and is reflected on y-axis.