This document defines key mathematical concepts such as expressions, equations, polynomials, and their properties. It discusses:
1) Mathematical expressions as well-formed symbolic representations composed of operands, operations, and relations.
2) Equations as propositions expressing an equality relationship between expressions. Solutions are values substituted for free variables that render an equation true.
3) Polynomials as expressions composed of coefficients and variables, with operations including addition, subtraction, multiplication, and non-negative exponentiation. The degree of a polynomial is determined by the greatest exponent.