1. Section 1-5 Algebra: Variables and Expressions

2. Vocabulary Algebra: Is a language of symbols, including variables Variable: Is a symbol, usually a letter, used to represent a number Algebraic expression: Are combinations of variables, numbers, and at least one operation Evaluate: Find the value

3. Example Evaluate 35 + x, if x=6 Replace the variable by its value, which is 6. 35+x= 35+6 =41

4. Examples N + 3 if n = 4 4 + 3 7 Evaluate if c = 8 a.C + 2 8 + 2 10 b.C – 3 8 – 3 5 c.15 – c 15 – 8 7

5. 8w – 2v if w=5 and v=3 85 - 23 40 - 23 40 - 6 34 mn 6 if m=8 and n=12 812 6 96 6 16

6. Y 2 + 2 if y=3 3 2 + 2 9 + 2 11 Evaluate if a=4 and b= 3 d.9a – 6b 94 - 63 36 - 63 36 – 18 18 e. ab 2 43 2 12 2 6 f. A 2 + 5 4 2 + 5 16 + 5 21