**Section 1: Like Terms and Unlike Terms**

**1. Terms, coefficient, and constant terms**

- The expression 2x – 3y + 8 consists of three terms. They are 2x, -3y and 8. The numerical part, including the sign, of a term is called the coefficient of the variable.
- Term 2x, the coefficient of x is 2
- Term -3y, the coefficient of y is -3
- Term 8, is called constant term

**2. Classify the like terms and unlike terms: explained in class**

**3. Simplify the algebraic expression by combining (or collecting) like terms**

- 2x + 3x = 5x
- 8y – 3y = 5y
- 3a + 4b – 2a + 5b = (3a -2a) + (4b +5b) = a + 9b

**4. Home Work:**

- Handout: two pages
- Workbook:
- page 21: 1, 2
- Page 22: 6, 9, 10

**Section 2: 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