Answer:
- 3. line y=x
- 4. 10 units to the right and 4 units up
Step-by-step explanation:
In the attached diagram, the green polygon A"B"C" is the reflection of ABC across the line y=x. Then the purple polygon A'B'C' is the translation of A"B"C" 10 units to the right and 4 units up.
_____
You can tell a reflection is involved, because the clockwise order of A, B, C in the original is reversed to counterclockwise in A'B'C'. The left-right horizontal line AC becomes the down-up vertical line A'C', so you know the reflection is across the line y=x, and not the line y=-x.
After the reflection, point A" is located at (2, -6), so moving it to A'(12, -2) entails a translation 10 units right and 4 units up.