Similar terms in algebra, sometimes referred to as like terms, are terms that contain the same variables raised to the same power. In algebraic expressions, terms cannot be combined unless they are similar terms.
Combining similar terms is a way to simplify algebraic expressions in order to make them easier to work with. For example, the equation 7xy - 4xy + 4x^2 + 5x^2 can be simplified by combining its similar terms. The terms that share variables and that are raised to the same power are 7xy and -4xy, as well as 4x^2 and 5x^2. When similar terms are combined, the equation reads 3xy + 9x^2.