Apply Order of Operations Warm Up Lesson Presentation Lesson Quiz

Warm-Up Evaluate the expression. 1. a + 5.7 when a = 1.3 ANSWER 7 2. b3 when b = 4 ANSWER 64

Warm-Up 3. The number of weeks it takes you to read a novel is given by , where n is total pages in the novel and p is pages read per week. How long will it take you to read a 340-page novel if you read 85 pages per week? n p ANSWER 4 weeks

Evaluate the expression 27 32 2 3. – Example 1 Evaluate the expression 27 32 2 3. – STEP 1 There are no grouping symbols, so go to Step 2. STEP 2 Evaluate powers. 27 32 2 – 3 = 27 9 2 – 3 Evaluate power. STEP 3 Multiply and divide from left to right. 27 9 2 – 3 = 3 2 – 3 Divide. 3 2 – 3 = 6 – 3 Multiply.

Add and subtract from left to right. Example 1 STEP 4 Add and subtract from left to right. 6 – 3 = 3 Subtract. ANSWER The value of the expression 27 32 2 – 3 is 3.

Guided Practice 1. Evaluate the expression 20 – 42 . ANSWER 4 2. Evaluate the expression 2 32 + 4 . ANSWER 22 3. Evaluate the expression 32 23 + 6 . ANSWER 10 4. Evaluate the expression 15 + 62 – 4 . ANSWER 47

Evaluate the expression. Example 2 Evaluate the expression. a. 7(13 – 8) = 7(5) Subtract within parentheses. = 35 Multiply. b. 24 – (32 + 1) = 24 – (9 + 1) Evaluate power. = 24 – 10 Add within parentheses. = 14 Subtract. c. 2[30 – (8 + 13)] = 2[30 – 21] c. Add within parentheses. = 2[9] Subtract within brackets. = 18 Multiply.

Guided Practice 5. Evaluate the expression 4(3 + 9) . ANSWER 48 6. Evaluate the expression 3(8 – 22) . ANSWER 12 7. Evaluate the expression 2[(9 + 3)  4] . ANSWER 6

Evaluate the expression when x = 4. Example 3 Evaluate the expression when x = 4. 9x 3(x + 2) = 3(4 + 2) 9 4 Substitute 4 for x. 3 6 9 4 = Add within parentheses. 18 36 = Multiply. = 2 Divide.

Guided Practice Evaluate the expression when y = 8. y2 – 3 8. = 61 12 – y – 1 9. = 3 10y + 1 y + 1 10. = 9

Example 4

The sponsor’s cost is $123.The correct answer is B. . A B C D ANSWER Example 4 SOLUTION 12(3j +2s) + 30 = 12(3 1.25 + 2 2) + 30 Substitute 1.25 for j and 2 for s. = 12(3.75 + 4) + 30 Multiply within parentheses. = 12(7.75) + 30 Add within parentheses. = 93 + 30 Multiply. Multiply. = 123 Add. The sponsor’s cost is $123.The correct answer is B. . A B C D ANSWER

Guided Practice WHAT IF? In Example 4, suppose the number of volunteers doubles. Does the sponsor’s cost double as well? Explain. No; the total cost of the juice drinks and sandwiches will double, but the cost of the trash bags will not. ANSWER

Lesson Quiz Evaluate the expression. 1. 33  9 + 4 3 ANSWER 15 2. 12 + (5 – 3)2 ANSWER 16 3. 2(c2 + 4 ) when c = 4 ANSWER 40 4. g2 – 8 2g – 5 when g = 6 ANSWER 4

Lesson Quiz 5. The cost (in dollars) to buy p posters at the Posters Plus online store is given by the expression 3.5p + 6.75. At the More Posters online store, the cost is given by 4.25p + 2.55. Which store has the lower cost for 5 posters? The cost at the More Posters online store is less. ANSWER