Equations are mathematical statements that assert the equality of two expressions, typically involving variables and constants. They are fundamental in various fields, including Physics, Engineering, and Economics, as they help describe relationships and solve problems. For example, the equation y = mx + b represents a linear relationship between x and y. Solving equations involves finding the values of the variables that make the equation true. This process is essential for understanding and modeling real-world situations. Equations can be simple, like x + 2 = 5, or complex, involving multiple variables and higher-order terms, but they all serve the purpose of establishing relationships between quantities.