Final answer:
A variable is a letter or symbol that represents a number that can change. In mathematics, it is used to describe something that is subject to change or is not constant.
Step-by-step explanation:
In mathematics, a variable is a letter or symbol that represents a number that can change. When using variable as an adjective, it describes something that is subject to change or is not constant.
For example, in the equation y = mx + b, the letter 'm' and 'b' are variables because they can take on different values. These values can change the slope and y-intercept of the line represented by the equation.
Variables are used extensively in algebra, where they allow us to solve equations, make predictions, and study patterns and relationships between quantities.
Learn more about Variables in Mathematics