This document provides instruction on algebra concepts including operations with intervals, theorems of inequalities, and the inequality of means. It covers union, intersection, difference, and complement of intervals. It also details six theorems of inequalities and provides proofs of three theorems regarding real numbers: a2 + b2 ≥ 2ab; 2a2 + b2 ≥ a + b2; and a2 + b2 + c2 ≥ ab + bc + ac. Finally, it explains the inequality of means and applies it to find minimum values of expressions involving positive variables.