An equation refers to an equation containing unknowns. It is an equation that represents the equal relationship between two mathematical expressions (such as two numbers, functions, quantities and operations), and the value of the unknown quantity that makes the equation hold is called "solution" or "root". The process of finding the solution of the equation is called "solving the equation".

By solving the equation, we can avoid the difficulty of reverse thinking and directly list the equations with the quantity to be solved. There are many forms of equations, such as one-dimensional linear equation, two-dimensional linear equation, one-dimensional quadratic equation and so on. , can also be combined into equations to solve multiple unknowns.

In mathematics, an equation is a statement containing one or more variables. Solving an equation involves determining which variables have values that make the equation valid. Variables are also called unknowns, and the value of the unknowns satisfying the equation is called the solution of the equation.

As early as 3600 years ago, the ancient Egyptians wrote mathematical problems on papyrus, involving equations with unknowns.

Around 825 AD, Al Hualazimi, a mathematician in Central Asia, wrote a book called "Elimination and Return", focusing on solving equations.

China's equation comes from the ancient mathematical monograph Nine Chapters Arithmetic, the eighth volume of which is called Equation. "Fang" means juxtaposition, and "Cheng" is a vertical form with calculation.

In the definition, the equation must be an equation, but there can be others, such as 1+ 1=2,100×10000 =10000, all of which are equations. Obviously, the range of the equation is a little larger.