Materials are inputs to production[?] or manufacturing. They are often raw - that is unprocessed, but are sometimes processed before being used in more advanced production processes. In general, in technologically advanced societies, the materials are not finished consumer goods.
... trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of b/(2a) to both sides, ...