Answer:
As trade in gold and salt increased, Ghana's rulers gained power. Eventually, they built up armies equipped with iron weapons that were superior to the weapons of nearby people. Over time, Ghana took control of trade from merchants. Merchants from the north and south then met to exchange goods in Ghana.
Explanation: Ghana's decline was caused by attacking invaders, overgrazing, and the loss of trade. 1. Invasion. – A Muslim group called the Almoravids cut off many trade.