In short: yes (with pivoting for numerical stability), but it's far from the only way, and in certain cases other methods may be better (for example, some method based on conjugate gradients is good when the matrix is sparse, and matrix decomposition is useful for when you want to solve Ax = b for several different b).
It is well known that a vector space always admits an algebraic (Hamel) basis. This is a theorem that follows from Zorn's lemma based on the Axiom of Choice (AC).
Now consider any specific instance of vector space. Since the AC axiom may or may not be included in the underlying set theory, might there be examples of vector spaces in which an Hamel basis actually doesn't exist ?