Final answer:
The expansion of commerce in the Hellenistic world was facilitated by the establishment of Hellenistic cities, cultural blending, and increased knowledge and exploration.
Step-by-step explanation:
The expansion of commerce in the Hellenistic world was a product of various factors such as the establishment of Hellenistic cities by Alexander the Great and his successors, the blending of Greek and other cultures, and the reign of the Seleucid and Ptolemaic dynasties. These cities fostered trade by introducing Greek institutions and amenities in the regions of the former Persian Empire. The growth of knowledge and exploration during this period, such as trading posts along the Red Sea and historical accounts of foreign lands translated into Greek, also played a significant role in the expansion of commerce. Ambassadors wrote about the customs of foreign lands, further encouraging trade relations and cultural exchange.