A mathematical equation is a statement that asserts the equality of two expressions. It typically contains numbers, variables, and mathematical operations such as addition, subtraction, multiplication, or division. For example, the equation 2x + 3 = 7 shows that when you substitute x with a specific value, both sides of the equation will be equal. Equations are fundamental in mathematics and are used to solve problems across various fields, including science and engineering. They can represent relationships between quantities, such as in algebra or geometry, and are essential for understanding concepts like functions and graphs.