Answer:
B. (0, 9)
Step-by-step explanation:
Reflection across x=a is represented by the transformation ...
... (x, y) ⇒(2a-x, y)
Reflection across y=b is represented by the transformation ...
... (x, y) ⇒ (x, 2b-y)
The double reflection, across x=2, y=1 will result in the transformation ...
... (x, y) ⇒ (2·2-x, y) ⇒ (4-x, 2·1-y) ⇒ (4-x, 2-y)
For (x, y) = X(4, -7), the transformed point is ...
... X''(4-4, 2-(-7)) = X''(0, 9)
