what will be the coordinates of B’ if the triangle below if reflected across the y-axis?I selected (-2,-1) double checking my answer

B'(-2, -1)
Explanations:When a point (x, y) is reflected across the y-axis, the coordinate of the image is (-x, y)
The coordinate of B is:
B(2, -1)
Therefore, the corrdinates of the image B' will be:
B'(-2, -1)