# Expressions, Equations, and Relationships: One-Variable Equations and Inequalities

Check out Math Explorations, a series of middle school math textbooks aligned to the TEKS!

(8)  Expressions, equations, and relationships. The student applies mathematical process standards to use one-variable equations or inequalities in problem situations. The student is expected to:

(A)  write one-variable equations or inequalities with variables on both sides that represent problems using rational number coefficients and constants;

(B)  write a corresponding real-world problem when given a one-variable equation or inequality with variables on both sides of the equal sign using rational number coefficients and constants;

(C)  model and solve one-variable equations with variables on both sides of the equal sign that represent mathematical and real-world problems using rational number coefficients and constants; and

(D)  use informal arguments to establish facts about the angle sum and exterior angle of triangles, the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.