Variables: A letter or symbol used to represent an unknown or changing quantity in an equation
or formula.
In mathematical equations and formulas, variables are used to represent unknown or changing quantities. They are usually denoted by letters or symbols, and their values can vary depending on the context of the problem being solved. For example, in the equation y = mx + b, the variables are y, x, m, and b. The value of y and x can change depending on the specific problem being solved, while m and b represent constants with fixed values. Variables can be used to describe a variety of physical and abstract quantities, such as time, temperature, distance, and probability, among others.