Elements of Algebra is a mathematical treatise by the famous mathematician Leonhard Euler, originally published circa 1765. Its title echoes that of Euclid's Elements. The Elements of Algebra contains many important early results in analysis; for example, it contains Euler's original proof of Fermat's Last Theorem for the special case of n=3.
In 1771, Joseph Lagrange published a follow-up volume entitled Additions to Euler's Elements of algebra, which featured a number of imprtant mathematical results.