Expressions and Equations

An equation is a mathematical statement that asserts the equality of two expressions, typically containing variables and constants.

A variable is a symbol (usually a letter) that represents an unknown value in an equation.

A constant is a fixed value that does not change, such as the number 5 or -3.

Subtract 2 from both sides to get 5r = 25, then divide by 5 to find r = 5.

A coefficient is a numerical factor in a term of an algebraic expression, such as the 8 in 8h.

Variables allow us to represent unknown quantities and formulate general mathematical statements.

An expression is a combination of numbers and variables without an equality sign, while an equation states that two expressions are equal.