The image of QRS after a reflection across the y-axis and a translation 6 units down is Q'R'S'.
Let's analyze the changes that have occurred to determine if the image is the same size and shape as the preimage:
1. Reflection across the y-axis: This transformation flips the figure horizontally. In this case, the points Q, R, and S will be reflected to the points Q', R', and S' respectively. The shape of the figure remains the same, but its orientation is reversed.
2. Translation 6 units down: This transformation moves the figure vertically downward by 6 units. Since the figure is moved uniformly, all points of the figure are translated down by the same distance. Therefore, the new points Q', R', and S' will be 6 units below their corresponding original points Q, R, and S.
Based on these transformations, we can conclude that the image Q'R'S' is the same shape as the preimage QRS. However, it is not the same size since it has been translated 6 units down.