This document discusses how to solve equations using addition and subtraction properties of equality. It explains that to solve an equation means to isolate the variable on one side. It then introduces the addition property of equality, which states that if a = b, then a + c = b + c, meaning any number can be added to both sides of an equation without changing whether it is true. Several examples are worked through to demonstrate adding and subtracting various numbers from both sides of an equation. Finally, the subtraction property of equality is presented similarly.