**Distributive Law, Addition and Subtraction of Linear Algebraic Expressions**

**1. Use of parentheses and distributive law**

- a(x + y) = ax + ay
- (x + y)a = a(x + y) = ax + ay = xa + xy
- a(x – y) = a{x + (-y)] = ax + a(-y) = ax – ay
- a(x + y + z) = ax + ay + az
- x – (a – b) = a -a + b

**2. Addition and subtraction of linear algebraic expressions: explained in class**

- (2a +3b) + (5a -4b) =
- Find the sum of -2p + 3q – 4 and p + 5q – 3
- (4x – 5) – (7x – 3)

**3. Home Work:**

- Handout:
- one pages

- Workbook:
- page 21: 3, 4, 5
- Page 23: 11, 12, 13, 14, 15
- Page 24: 21
- Page 25: 22, 23