The “rule of quantity” in Spanish Algebras of the 16th century. Possible sources.

The paper analyses the treatment of the systems of equations by the more notable authors of the Iberian Peninsula in the 16th Century. The works studied allows us to show the evolution of these systems. It was very important in the process of algebraizationof the mathematics. Some hypotheses about the sources that inspired the authors studied have been proposed.Key words: Algebra, Systems of equations, Iberian Peninsula, 16th Century.The paper analyses the treatment of the systems of equations by the more notable authors of the Iberian Peninsula in the 16th Century. The works studied allows us to show the evolution of these systems. It was very important in the process of algebraization of the mathematics. Some hypotheses about the sources that inspired the authors studied have been proposed.Key words: Algebra, Systems of equations, Iberian Peninsula, 16th Century