How were the economies of ancient Mesopotamia , Egypt and the Indus Valley similar?

They were all based on the development of agriculture and later trades and crafts.

Explanation:

The oldest civilizations, including this ones were created in the river valleys, where the first permanent settlements were created.

With the development of irrigational systems, the agriculture was introduced as a main source of profit. Of course, later different labors, including certain crafts were introduced, and then a trade between these regions.