Why did the pharaoh in egypt free the hebrews

Explanation: Pharaoh refused for a couple of reasons. One was the perceived financial loss if all the free labor would cease, as he himself implied (Exodus 14:5). Another was sheer obstinacy, in which he hardened his heart.

A careful reading of Exodus (ch.7-12), at least in the original Hebrew, reveals that Pharaoh hardened his own heart in most of the plagues. God only hardened Pharaoh's heart in three of the ten plagues: the sixth, eighth and ninth. That's all.  

Then after the last plague Pharaoh was angry and released the Israelite to go to the promised land

social status of early civilizations was based primarily on economic power.- true ( first choice)

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.