Final answer:
The vertices of triangle A'B'C' would be (9, 9), (3, 6), and (0, 12).
Step-by-step explanation:
To reflect a point over the y-axis, we change the sign of its x-coordinate.
So, the new coordinates of point A' would be (3, 3) since the x-coordinate (-3) becomes positive.
To dilate a point by a scale factor of 3, we multiply both coordinates by 3.
So, the new coordinates of point A'' would be (9, 9) since we multiplied both the x-coordinate and y-coordinate of A' by 3.
Similarly, for points B and C, we follow the same process to find the coordinates of B' and C', and then multiply both coordinates by 3 to find the coordinates of B'' and C''.
The vertices of triangle A'B'C' would be (9, 9), (3, 6), and (0, 12).