Final answer:
Like terms are terms in an algebraic expression that have the same variable and exponent. They can be added or subtracted to simplify expressions. Different variables or exponents mean the terms are not like terms.
Step-by-step explanation:
Like terms in an algebraic expression are terms that have the same variable(s) and the same exponent(s). This means that in addition to having the same variables, the powers to which these variables are raised must also be identical. For example, in the terms 3x2 and 5x2, the variable is 'x' and the exponent is '2'. Since both terms share these components, they are considered like terms and can be combined to simplify expressions through addition or subtraction.
However, terms like 3x2 and 5x3 are not like terms because they have different exponents. Likewise, terms that have different variables cannot be considered like terms, even if they have the same exponents, such as 3x2 and 3y2. This understanding is essential in ensuring that expressions and equations maintain dimensional consistency. In other words, each side of an equation must have the same dimensions for the equation to be valid.