Main Idea and New Vocabulary Example 1: Translate Phrases into Algebraic Expressions Example 2: Translate Phrases into Algebraic Expressions Example 3: Evaluate Algebraic Expressions Example 4: Evaluate Algebraic Expressions Example 5: Evaluate Algebraic Expressions Example 6: Real-World Example: Use Expressions to Solve Problems Lesson Menu

Translate verbal phrases into algebraic expressions Translate verbal phrases into algebraic expressions. Evaluate algebraic expressions. variable algebra algebraic expression defining a variable Main Idea/Vocabulary

Translate Phrases into Algebraic Expressions Translate seven dollars more than John has into an algebraic expression. Answer: 7 + d Example 1

Translate nine more books than Maria has into an algebraic expression. A. 9b B. 9 + b C. 9 – b D. 9b + 1 Example 1 CYP

Translate Phrases into Algebraic Expressions Translate Mrs. Ruiz had 50 pens and gave 2 to each of her students into an algebraic expression. Answer: 50 – 2s Example 2

Translate Mark had 20 guitar picks and gave 3 to each of his friends into an algebraic expression. A. 20 + f B. 20 + 3f C. 20 – f D. 20 – 3f Example 2 CYP

Evaluate Algebraic Expressions Evaluate (x – y) + 3 ● (–2) if x = –4 and y = 5. (x – y) + 3 ● (–2) = (–4 – 5) + 3 ● (–2) Replace x with –4 and y with 5. = –9 + 3 ● (–2) Perform operations in the parentheses first. = –9 + –6 or –15 Multiply 3 and –2. Then add. Answer: –15 Example 3

Evaluate (x + y) + 2 ● (–4) if x = 3 and y = –6. B. –11 C. –5 D. 4 Example 3 CYP

Evaluate Algebraic Expressions Evaluate 3(a – b) ÷ 2 if a = 8 and b = 4. 3(a – b) ÷ 2 = 3(8 – 4) ÷ 2 Replace a with 8 and b with 4. = 3(4) ÷ 2 Perform operations in the parentheses first. = 12 ÷ 2 or 6 Multiply 3 and 4. Then divide. Answer: 6 Example 4

Evaluate 5(a – b) ÷ 4 if a = 7 and b = 3. C. 6 D. 10 Example 4 CYP

Evaluate Algebraic Expressions Evaluate if c = 2 and d = 6. Replace c with 2 and d with 6. Simplify. Evaluate the numerator and denominator. Then divide. Answer: 2 Example 5

Evaluate if c = 9 and d = –6. A. –1 B. C. 1 D. Example 5 CYP

Use Expressions to Solve Problems KAYAKS River Rentals rents kayaks. They charge a $10 service charge plus $3 per hour. Write an expression that can be used to find the total cost to rent a kayak for any number of hours. Answer: The expression is 10 + 3h. Example 6

KAYAKS River Rentals rents kayaks KAYAKS River Rentals rents kayaks. They charge a $10 service charge plus $3 per hour. What is the total cost to rent a kayak for 3 hours? A. $13 B. $16 C. $19 D. $33 Example 6 CYP