Longest-standing maths problem ever

Andrew Wiles (UK) at Princeton University in New Jersey, USA, proved Fermat's Last Theorem in 1995. He showed that xⁿ+yⁿ=zⁿ has no solutions in integers for n being greater than 2. The theorum was posed by Fermat in 1637, and stood for 358 years.

French mathematician Pierre de Fermat (1601–1665) pencilled a note in the margin of his copy of the Arithmetica by the Ancient Greek "father of algebra" Diophantus of Alexandria (c. 250 CE) that read: "It is impossible for a cube to be a sum of two cubes, a fourth power to be a sum of two fourth powers, or in general for any number that is a power greater than the second to be the sum of two like powers. I have discovered a truly remarkable proof, but this margin is too small to contain it." The note was found after Fermat's death, and for centuries, it teased mathematicians unable to prove or disprove it. It was finally cracked by (now Sir) Andrew John Wiles with the help of former student Richard Taylor. The proof was published in 1995 in the journal Annals of Mathematics and earned WIles the King of Norway's Abel Prize, the Royal Society's Copley medal, and a knighthood.