Question

The coordinates of a quadrilateral are (5, 8), (7, 10), (9, 12), and (11, 14). After a transformation, the sign of the x-coordinate and the sign of the y-coordinate for each ordered pair have changed. Which type of transformation occurred?
A) 180° rotation
B) (x,y)→(x + 2, y + 2)
C) reflection across the y-axis
D) reflection across the x-axis

Answer 1

Sign changing means that each value went from positive to negative. 

Assuming A is a 180 degree rotation around the origin, the answer would be A.

B doesn't change the sign for neither x nor y.
C changes the sign for y, but not x.
D changes the sign for x, but not y.