Question

ABC is reflected across x = 1 and y = -3. What are the coordinates of the reflection image of B after both reflections?A. (-7, -1)B. (-7, 1)C. (7, 1)D. (7, -1)

Answer 1

The correct option is C.

Explanation:

From the given figure it is noticed that the coordinates of B are (-5,-7).

If ABC is reflected across x = 1, then

`(x,y)\rightarrow(1-(x-1),y)`

`(x,y)\rightarrow(2-x,y)`

`(-5,-7)\rightarrow(2+5,-7)`

`(-5,-7)\rightarrow(7,-7)`

If ABC is reflected across y =-3.

`(x,y)\rightarrow(x,-3-(y-(-3)))`

`(x,y)\rightarrow(x,-6-y)`

`(7,-7)\rightarrow(7,-6-(-7))`

`(7,-7)\rightarrow(7,1)`

Therefore option C is correct.