E773  Solutio problematis difficillimi, quo hae duae formulae aaxx + bbyy et aayy + bbxx quadrata reddi debent
(A solution of a most difficult problem, in which the two forms aaxx + bbyy et aayy + bbxx must be rendered into squares)
Summary:
Euler first finds three families of particular solutions, then proceeds to a general solution. Finally, he extends the problem to
finding a, b, c, and d that make the following three expressions all squares:
aabb + ccdd, aacc + bbdd, aadd + bbcc.
Publication:

Originally published in Memoires de l'academie des sciences de St.Petersbourg 11, 1830, pp. 1230

Opera Omnia: Series 1, Volume 5, pp. 94  115
 Reprinted in Commentat. arithm. 2, 1849, pp. 425437 [E773a]
Documents Available:
 Original publication: E773
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