When you have a point A and then transform it using a linear transformation (like rotation, reflections, etc.), we mark it as A' to say, "This is the point which corresponds to A after the transformations were applied". This establishes a link between the two, even though they may appear to be unrelated to someone looking at the graph.
Answer:
The answer is the first one -8x.
(4/9) divided by (2/3) is 2/3 because you do the reciprocal and mul. Then you mult it by the reciprocal of (5/6) which is (6/5) and get 4/5