In studies carried out in the 1980s the algebraic symbols and expressions are revealed through prealgebraic readers as non-independent texts, as texts that relate to other texts that in some cases belong to the reader's native language or to the arithmetic sign system. Such outcomes suggest that the act of reading algebraic texts submerges the reader into a network of intertextual relations derived from that reader's prior mathematics and linguistic experiences. In this article we propose an analytical perspective of algebraic activity that is based on intertextuality and that makes it possible to advance our knowledge concerning the production of sense in said activity. In particular, we resort to the notion of intertextuality as a means of theoretically describing and explaining sense production processes in the learning of two algebraic methods: the Cartesian Method (for the algebraic solution of word problems) and the Substitution Method (for the solution of systems of two linear equations with two unknowns). We support our arguments via a series of episodes of empirical study interviews with secondary school students, in order to demonstrate the pertinence and relevance of carrying out their analysis from the perspective proposed.