1. Variables and Expressions

2. The branch of mathematics that involves expressions with variables is called algebra. n + 2 This is an algebraic expression because it contains variables, numbers and at least one operation

3. Example: Evaluate n + 3 if n = 4. n+ 34= 7 Evaluate c – 5 if c = 11. c– 5 11 = 6 R O C K S T A R

4. More examples: Evaluate each expression if c = 8 and d = 5. c + d 8 + 5= 13 15 – c + d 15 – 8 + 5 = 12

5. In algebra, sometimes the multiplication sign is omitted. 6d6d6d6d 9st mn six times d nine times s times t m times n

6. Don’t forget PEMDAS!! Let’s work it out! Evaluate 8w – 2y if w = 5 and y = 3. 8w – 2y 8(5) – 2(3) 40 – 6 34

7. Evaluate 4c 2 + 2 if c = 3. 4c 2 + 2 4(3) 2 + 2 4(9) + 2 38 **PEMDAS** 36 + 2

8. Last one! Evaluate (5 + g) 2 if g = 3. Evaluate (5 + g) 2 if g = 3. 2 (5 + g) 2 2 (5 + 3) 2 2 (8) 2 2 64 2 == 32

9. Your assignment… Page 46 #14 – 32 evens Page 46 #14 – 32 evens 10 problems! DO YOUR BEST!