Answer:
The coordinates of B will be (3,-4).
Explanation:
If a point on the coordinate plane reflects across the y-axis then its y-coordinate will not alter but the x-coordinate will change by its sign only.
Now, if B'(-3,-4) is the image of B after a reflection in the y-axis then we can say B is the image point when the original point is B'(-3,-4) after reflection in the y-axis.
Therefore, the coordinates of B will be (3,-4). (Answer)