Coefficient matching feels rather natural when solving equations and checking dimensions, however in footnote 2 to "Two alternative derivations of Bridgman's theorem" (Berberan-Santos M N, Pogliani L, J. Math Chem 1999, 26, 255-261; p256) it's mentioned that Descartes shifted from line/area/volume ideas to the basic number line view.
Is this where the idea of coefficient matching between the terms when solving polynomials began, or was it already well established for pure number polynomials?