two or more monomials that contain the same variables raised to the same powers, regardless of their coefficients. For example, 2x²y  and -8x²y are like terms because they have the same variables raised to the same exponents.

a number, a variable, or a product of a number and one or more variables with whole number exponents, such as -5,  x, and 8xy³

a monomial or sum of monomials, like 4x² + 3x – 10