If 6x and 4x are congruent what is the value of x

When reading a textbook blank. a) it’s safe to assume that the ingot is not biased b) you should watch for fallacies in information and author bias c) you should fact check everything you read d) it is understood that academic sources are not biased

Who developed the theory of plate tectonics?

What empire controlled most of the middle east except for a few years between 1516 and 1917, where was the capital of this empire located and what was the geographic extent of this empire?