By the thirteenth century, the political and religious influence of islam traveled further south because of?

It traveled further because Islam was successful in two things. The first thing is its success in recruiting or rather convincing new people that it was the faith that should be followed. For that reason it gained many followers around the world, and especially in the south. Another reason was that they achieved important military victories during those times which increased and expanded the islamic belief. 

The right answer on edge is: I need to change my budget so that I save at least $300 per month. Over twelve months, this will increase my savings by $3,600. I also need to change my budget to save for a new computer, so I need to save an extra $100 a month for that. In total, I need to save $400 a month.