By the way people began to listen to his ideas
Islam spread from Arabia.
Islam
The religion of Islam.
ISLAM
Islam spread to all corners of the Arab World: North Africa, the Upper Middle East, and Arabia.
It spread to places in Saudi Arabia and Syria
I don't know, this is why I'm having trouble too.
trading and science advancement
Check the map. Islam was created in, and spread from, Arabia. Those countries closest to Arabia, of which Egypt is certainly one, were the first to feel the weight of Islamic armies.
75 to 100 years
75 to 100 years
By physical conquest.