Algebra is a branch of mathematics that deals with mathematical symbols and the rules for manipulating these symbols. Algebra is used to study relationships between numbers and quantities and to solve equations.

Some basic concepts in algebra include variables, expressions, and equations. A variable is a symbol that represents an unknown value, such as x or y. An expression is a combination of numbers and variables, such as 2x + 3. An equation is a statement that two expressions are equal, such as 2x + 3 = 7.