An equation is a mathematical statement that asserts the equality of two expressions. It is composed of two sides, the left side and the right side, separated by an equal sign (=). For instance, in the equation 2x + 3 = 7, the left side consists of the expression 2x + 3 and the right side is the number 7.
Equations can represent various types of relationships and can involve constants, variables, and arithmetic operations. The main goal when working with equations is often to find the value of the variables that make the equation true. In the example above, solving the equation entails isolating the variable x, which in this case leads to the solution x = 2.
Equations are fundamental in mathematics and are used across different fields, including science and engineering, because they help to describe and model real-world situations and relationships quantitatively.