Why was Northern Africa isolated from the rest of the continent

The Sahara becomes the almost impenetrable barrier which throughout recorded history has separated the Mediterranean coast and north Africa from the rest of the continent. Hope this help ever thought I'm not a history  I'm a math guy!

Explanation:

answer

explanation

the given equation is

we can rewrite this as:

let

then the equation becomes:

the factors of 8 that sum up to -9 are {-1,-8}

we split the middle term with these factors to obtain,

we factor by grouping to obtain:

apply the zero product property to get:

but

the main reason the us senate rejected the treaty of versailles was because "european nations wanted to punish germany"

d(:

me and mark as brainliest.