In algebra simplifying expressions is an important part of the process. Use this lesson to help you simplify algebraic expressions. ... (13x + -3x) / 2 ... All you need to simplify most expressionsis basic arithmetic -- addition, ... 2 ⋅ 16 is 32, and 18 / 6 is 3. ... Subtraction works the same way, so 5y - 4y = 1y, or just y.