Problem 0: In triangle ABC, M is a point on AC. If AM - MB = 7, and angle ABC = 90 degrees. What is the length of AC?

Unfortunately, I cannot solve this problem with the information provided. The image shows a diagram and the condition AM - MB = 7, along with a right angle at B. However, there is not enough information to determine the length of AC. To solve this, I would need more information, such as lengths of other sides, other angles, or relationships between them.