find a coordinate of B' after a 180° rotation of the triangle about the origin and then a reflection about the x = 2.

Answer:
B' = (5, -4)
Step-by-step explanation:
The picture is illegible, but we think B is (1, 4).
After rotation 180°, both coordinates are negated, so the point is ...
B" = -(1, 4) = (-1, -4)
After reflection across x=2, the x-coordinate is subtracted from 2·2 = 4:
B' = (4 -(-1), -4)
B' = (5, -4)