Answer:
the rotated point B is then at (3, -7)
Explanation:
the specification says a rotation of -90 degrees (counter clockwise) around the point (0, 0).
a turn by 90 degrees in any direction brings it always into the next quadrant, because every quadrant represents 90 degrees.
the rotated point will have the same distance from the center, of course. and the angle of the connection line center to B to the negative x-axis will be then the same as the angle of the connection line to the rotated point to the negative y-axis.
just think about rotating the original graph by -90 degrees. point B stays on the grid were it is and moves with the grid, and we just flip the coordinate axis.
so, it will be (3, -7).