A formula is a mathematical expression that shows the relationship between different quantities. It often uses symbols and numbers to represent specific values or operations. For example, the formula for the area of a rectangle is A = l × w, where A is the area, l is the length, and w is the width. Formulas are essential in various fields, including science, engineering, and finance, as they help solve problems and make calculations easier. In addition to mathematics, formulas can also be found in chemistry, where they represent the composition of substances. For instance, the formula for water is H2O, indicating that each molecule consists of two hydrogen atoms and one oxygen atom. Understanding formulas allows individuals to analyze data, predict outcomes, and communicate complex ideas clearly.