Final answer:
Paragraphs 7-9 contribute by outlining Alexander the Great's empire expansion and his role in spreading Greek culture during the Hellenistic period.
Step-by-step explanation:
In the context of a history text, paragraphs 7-9 contribute to the development of ideas by describing a period of expansion for Alexander the Great's empire. These paragraphs would provide details about how after inheriting his father King Philip II's plan, Alexander the Great successfully waged war against the Persian Empire and eventually claimed the Persian throne. Furthermore, his conquests played a significant role in spreading Greek culture throughout the regions he conquered, exemplified by the founding of Greek cities and the blending of cultures in the Hellenistic period.