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Example of a polynomial equation, studied in elementary algebra

Algebra is the branch of mathematics that studies certain abstract systems, known as algebraic structures, and the manipulation of statements within these systems. Elementary algebra generalizes arithmetic by using variables in addition to numbers. It covers methods of transforming equations to solve them by isolating variables. Linear algebra examines systems of several linear equations and techniques to determine for which values all equations in a system are true at the same time. Abstract algebra investigates algebraic structures, which consist of a set of objects together with operations defined on that set. It distinguishes algebraic structures, such as groups, rings, and fields, based on their number of operations and the laws they follow. Algebraic methods were first studied in ancient times to solve specific problems. As algebra evolved, it became increasingly abstract and generalized, leading to many applications in other branches of mathematics and the empirical sciences. (Full article...)

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Carlyle Hotel

... that a staff member at the Carlyle Hotel (pictured) once lent his own bow tie to Laurence Olivier?
... that Yangginu plotted to defeat Khan Wan to avenge his murdered father?
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... that the city council of Hamtramck, led by Mayor Amer Ghalib, banned the pride flag from publicly owned flagpoles?
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... that U.S. Army chaplain Patrick Ryan celebrated a Mass of thanksgiving for 10,000 people after the liberation of Rome?
... that Perplexities after Escher, a composition for heckelphone, string quartet and double bass, is based on five graphic artworks by M. C. Escher?

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On this day

December 12: Beginning of the Yule Lads' arrival in Iceland

George W. Bush

627 – At the Battle of Nineveh, the Byzantine army under Emperor Heraclius defeated the forces of Sasanian emperor Khosrow II, commanded by Rhahzadh, near present-day Mosul, Iraq.
1936 – Republic of China leader Chiang Kai-shek was kidnapped by Marshal Chang Hsueh-liang, a former warlord of Manchuria.
1988 – Three trains collided near Clapham Junction railway station in London, killing 35 people and injuring 484 others.
2000 – The U.S. Supreme Court ruled in Bush v. Gore that the recount of ballots cast in Florida for the presidential election be stopped, effectively making George W. Bush (pictured) the winner.
2021 – At the season-ending Abu Dhabi Grand Prix, Max Verstappen overtook Lewis Hamilton on the final lap to become World Drivers' Champion.

Geoffrey (d. 1212)
Edvard Munch (b. 1863)
Ikuhiko Hata (b. 1932)
Maʻafu Tukuiʻaulahi (d. 2021)

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Marcelo Rebelo de Sousa (born 12 December 1948) is a Portuguese politician and academic. He has been the 20th and current president of Portugal since 9 March 2016. As a member of the Social Democratic Party, he previously served as a minister and parliamentarian in the Assembly of the Republic. This photograph of Rebelo de Sousa was taken in 2017 at Web Summit, an annual technology conference held in Lisbon.

Photograph credit: João Pedro Correia

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