A geometric approach to equal sums of fifth powers

Most of the known results about the Diophantine equation x⁵ + y⁵ + z⁵ = u⁵ + v⁵ + w⁵ are shown to be particular instances of a simple geometrical construction. By studying a K3 surface contained in the fourfold, we show that there are an infinity of parametric solutions also satisfying x + y + z = u + v + w, x ? y = u ? v; and we show that these may be effectively determined.