Equation

In mathematics, an equation is an equality containing one or more variables. Solving the equation consists of determining which values of the variables make the equality true. In this situation, variables are also known as unknowns and the values which satisfy the equality are known as solutions. An equation differs from an identity in that an equation is not necessarily true for all possible values of the variable.

There are many types of equations, and they are found in many areas of mathematics. The techniques used to examine them differ according to their type.

Algebra studies two main families of equations: polynomial equations and, among them, linear equations. Polynomial equations have the form P(x) = 0, where P is a polynomial. Linear equations have the form a(x) + b = 0, where a is a linear function and b is a vector. To solve them, one uses algorithmic or geometric techniques, coming from linear algebra or mathematical analysis. Changing the domain of a function can change the problem considerably. Algebra also studies Diophantine equations where the coefficients and solutions are integers. The techniques used are different and come from number theory. These equations are difficult in general; one often searches just to find the existence or absence of a solution, and, if they exist, to count the number of solutions.

World of Tanks

World of Tanks is a massively multiplayer online game developed by Belarusian-Cypriot company Wargaming, featuring early to mid-20th century era fighting vehicles. It is built upon a freemium business model where the game is free-to-play, but participants also have the option of paying a fee for use of "premium" features. The focus is on player vs. player gameplay with each player controlling an armored vehicle, which may be a light, medium or heavy tank, tank destroyer, or self-propelled gun. World of Tanks debuted as an eSports game at the World Cyber Games 2012.

On 10 June 2013 it was announced that World of Tanks was coming to Xbox Live Arcade on 12 February 2014 as World of Tanks: Xbox 360 Edition. Xbox 360 players use separate servers to those playing the Windows version, and players of each version have separate accounts. The Xbox 360 version was developed by Wargaming West studio. An Xbox One version has been announced, and was released on 28 July 2015. A PlayStation 4 version is scheduled to release in 2016.World of Tanks has also recently expanded to mobile platforms under the name World of Tanks Blitz, in addition to a board game titled World of Tanks Rush and a collectable card game titled World of Tanks: Generals.

Tank

A tank is a large, heavily armoured fighting vehicle with tracks and a large tank gun that is designed for front-line combat. Modern tanks are mobile land weapon platforms, mounting a large-calibre cannon in a rotating gun turret. They combine this with heavy vehicle armour which provides protection for the crew, the vehicle's weapons, and its propulsion systems, and operational mobility, due to its use of tracks rather than wheels, which allows the tank to move over rugged terrain and be positioned on the battlefield in advantageous locations. These features enable the tank to perform well in a tactical situation: the combination of powerful weapons fire from their tank gun and their ability to resist enemy fire means the tank can take hold of and control an area and prevent other enemy vehicles from advancing. In both offensive and defensive roles, they are powerful units able to perform key primary tasks required of armoured units on the battlefield. The modern tank was the result of a century of development from the first primitive armoured vehicles, due to improvements in technology such as the internal combustion engine, which allowed the rapid movement of heavy armoured vehicles. As a result of these advances, tanks underwent tremendous shifts in capability during the World Wars of the 20th century.

World

World is a common name for the whole of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth or pertaining to anywhere on Earth.

In a philosophical context it may refer to:

In a theological context, world usually refers to the material or the profane sphere, as opposed to the celestial, spiritual, transcendent or sacred. The "end of the world" refers to scenarios of the final end of human history, often in religious contexts.

World history is commonly understood as spanning the major geopolitical developments of about five millennia, from the first civilizations to the present.

World population is the sum of all human populations at any time; similarly, world economy is the sum of the economies of all societies (all countries), especially in the context of globalization. Terms like world championship, gross world product, world flags etc. also imply the sum or combination of all current-day sovereign states.