To reflect the points A, B, and C across the y-axis, we need to change the sign of the x-coordinates while keeping the y-coordinates the same. The new coordinates can be calculated as follows:
Given the original coordinates:
- A (1, 5)
- B (9, 5)
- C (7, 2)
We apply the reflection across the y-axis:
-
For point A (1, 5):
- A' = (-1, 5)
-
For point B (9, 5):
- B' = (-9, 5)
-
For point C (7, 2):
- C' = (-7, 2)
So, the new coordinates after reflection across the y-axis are:
- A'(-1, 5)
- B'(-9, 5)
- C'(-7, 2)
These are the coordinates for points A", B", and C" after the reflection.