1. Holt CA Course 2 Writing Algebraic Expressions 1-2 Warm Up Warm Up California Standards California Standards Lesson Presentation Lesson PresentationPreview

2. Holt CA Course 2 Writing Algebraic Expressions 1-2 Warm Up Evaluate each expression for the given values of the variables. Which operation symbol goes with each word? 23 18 1 +    4. Sum5. Product 6. Quotient7. Difference 1. 9y – 13 for y = 4 2. 6n + 2p for n = 2 and p = 3 3. 3x – y for x = 1 and y = 2

3. Holt CA Course 2 Writing Algebraic Expressions 1-2 AF1.1 Use variables and appropriate operations to write an expression, an equation, an inequality, or a system of equations or inequalities that represents a verbal description (e.g., three less than a number, half as large as area A). California Standards

4. Holt CA Course 2 Writing Algebraic Expressions 1-2 a number plus 5 sum of a number and 5 5 more than a number subtract 11 from a number difference of a number and 11 11 less than a number 3 multiplied by a number product of 3 and a number 7 divided into a number quotient of a number and 7 n + 5 x – 11 3  m or 3m or a  7 a 7 Word PhrasesExpression + –  

5. Holt CA Course 2 Writing Algebraic Expressions 1-2 Write an algebraic expression for each word phrase. Additional Example 1: Translating Word Phrases into Math Expressions A. 9 less than a number w 9 less than a number w w – 9 B. 3 increased by the difference of p and 5 3 increased by the difference of p and 5 3 + (p – 5)

6. Holt CA Course 2 Writing Algebraic Expressions 1-2 Write an algebraic expression for each word phrase. Check It Out! Example 1 A. 88 times the difference of h and 4 88 times the difference of h and 4 88 (h – 4) B. the quotient of a number f and 6 quotient of f and 6 f  6 f 6

7. Holt CA Course 2 Writing Algebraic Expressions 1-2 Write a word phrase for the algebraic expression 9 – 3c. Additional Example 2: Translating Math Expressions into Word Phrases 9 – 3c 9 minus the product of 3 and c

8. Holt CA Course 2 Writing Algebraic Expressions 1-2 Check It Out! Example 2 Write a word phrase for the algebraic expression 7 + 19b. 7 + 19b 7 plus the product of 19 and b

9. Holt CA Course 2 Writing Algebraic Expressions 1-2 To solve a word problem, first interpret the action you need to perform and then choose the correct operation for that action.

10. Holt CA Course 2 Writing Algebraic Expressions 1-2 A restaurant leased its banquet hall for a function. The cost was $10 per person. Write an algebraic expression to determine what the cost would be if n people attended the function. Then evaluate the expression for 20, 21, 22, or 23 people. Additional Example 3: Writing and Evaluating Expressions in Word Problems $10 nCombine n equal amounts of $10. 10nCost in dollars 20 10(20) $200 21 10(21) $210 22 10(22) $220 23 10(23) $230 Evaluate for n = 20, 21, 22, and 23. n10nCost

11. Holt CA Course 2 Writing Algebraic Expressions 1-2 Gasoline costs $1.99 per n gallons. What will the cost be for 10, 12, 14, and 15 gallons? Check It Out! Example 3 $1.99 nCombine n equal amounts of $1.99. 1.99nCost in dollars 10 1.99(10) $19.90 12 1.99(12) $23.88 14 1.99(14) $27.86 15 1.99(15) $29.85 Evaluate for n = 10, 12, 14, and 15. n1.99nCost

12. Holt CA Course 2 Writing Algebraic Expressions 1-2 Write a word problem that can be evaluated by the algebraic expression 27 + t, and evaluate the expression for t = 1.76. Additional Example 4: Writing a Word Problem from a Math Expression Possible answer: Amed bought a new sweater for $27 plus sales tax t. If the tax was $1.76, what was the total cost of the sweater? 27 + t 27 + 1.76 = 28.76 Substitute 1.76 for t. The total cost of the sweater was $28.76.

13. Holt CA Course 2 Writing Algebraic Expressions 1-2 Write a word problem that can be evaluated by the algebraic expression 43 – d, and evaluate the expression for d = 10.24. Check It Out! Example 4 Possible answer: Tina bought a new jacket for $43 minus a store credit. If the store credit was $10.24, what did Tina pay for the jacket? 43 – d 43 – 10.24 = 32.76 Substitute 10.24 for d. Tina paid $32.76 for the jacket.

14. Holt CA Course 2 Writing Algebraic Expressions 1-2 Lesson Quiz Write an algebraic expression for each word phrase. 1. 5 less than a number k 2. a number x divided by 11 3. 4 times the sum of n and 5 Write an algebraic expression to evaluate the word problem. 4. Karen buys n raffle tickets for $0.50 each. If she buys 13 of them, how much will they cost? k – 5 4(n + 5) 0.50n; $6.50 x 11