The <u>graph</u> shows the <u>costs</u> of <u>purchasing</u> two types of flowers.
Select some value for x and draw vertical line
This line intersects the graphs of Flower A and the graph of Flower B in points A and B, respectively. The point A lies on this vertical line higher than the point B. This means that y-coordinate of point A is greater than y-coordinate of point B.
If y-coordinate of point A is greater than y-coordinate of point B, then Flower A is more expensive than Flower B (or Flower B is less expensive than Flower A).