A translation 2 units downward and reflection about the y-axis.
Step-by-step explanation:
The sequence of transformations that is applied to the quadrilateral ABCD to map onto the quadrilateral A"BC"D" is:
A translation 2 units downwards and then a reflection of the quadrilateral about y-axis.
( Since on translating two units downward all the coordinates of the vertex of the quadrilateral will be shifted two units down i.e. there will be a change in y-values and no change in x-values of the coordinates; and hence on reflecting about the y-axis, the image A"B"C"D" will be obtained )
