Question

If triangle ABC is reflected across the y-axis, what are the coordinates
of A'?
(4, -5)
(-5, 4)
(-4, 5)
(5, -4)

Answer 1

Answer: Second choice.  (-5,4)

Point A is located at (5,4)

To reflect over the y axis, we flip the sign of the x coordinate while keeping the y coordinate the same. The rule is $(x,y) \to (-x,y)$

So we will have $(5,4) \to (-5,4)$ as the location of A'