1. Splash Screen

2. Five-Minute Check (over Lesson 3–4) Then/Now New Vocabulary
Example 1: Real-World Example: Analyze Data with Matrices
Key Concept: Adding and Subtracting Matrices
Example 2: Add and Subtract Matrices
Key Concept: Multiplying by a Scalar
Example 3: Multiply a Matrix by a Scalar
Key Concept: Properties of Matrix Operations
Example 4: Multi-Step Operations
Example 5: Real-World Example: Use Multi-Step Operations with Matrices
Lesson Menu

3. maximum: f(4, 4) = 4 minimum: f(4, 11) = –10
Graph the system of inequalities. Name the coordinates of the vertices of the feasible region. Find the maximum an minimum values of the given function for this region. 1 ≤ x ≤ 4, y ≥ x, y ≥ 2x + 3; f(x, y) = 3x – 2y
maximum: f(4, 4) = 4 minimum: f(4, 11) = –10
B. maximum: f(4, 11) = 10 minimum: f(1, 1) = 1
C. maximum: f(4, 4) = 4 minimum: f(1, 5) = –7
D. maximum: f(4, 11) = 10 minimum: f(4, 4) = 4
5-Minute Check 1

4. A company profits $3 for every widget it manufactures and $2 for every plinket it manufactures. It must make at least one widget and one plinket each hour, but cannot make more than 7 total widgets and plinkets in any hour. What is the most profit the company can make in any hour?
A. $21
B. $20
C. $18
D. $5
5-Minute Check 2

5. You organized data into matrices.
Analyze data in matrices.
Perform algebraic operations with matrices.
Then/Now

6. scalar multiplication
Vocabulary

7. Analyze Data with Matrices
A. Use the matrix below that includes information on tuition (T), room and board (R/B), and enrollment (E) for three universities.
ISU UI
UNI
T R/B E
Find the average of the elements in column 1, and interpret the result.
Example 1

8. Answer: The average tuition cost for the three universities is $5935.
Analyze Data with Matrices
Answer: The average tuition cost for the three universities is $5935.
Example 1

9. Which university’s total cost is the lowest?
Analyze Data with Matrices
B. Use the matrix below that includes information on tuition (T), room and board (R/B), and enrollment (E) for three universities.
ISU UI
UNI
T R/B E
Which university’s total cost is the lowest?
Example 1

10. Answer: University of Northern Iowa
Analyze Data with Matrices
ISU = = $12,118
UI = = $13,543
UNI = = $11,632
Answer: University of Northern Iowa
Example 1

11. Analyze Data with Matrices
C. Use the matrix below that includes information on tuition (T), room and board (R/B), and enrollment (E) for three universities.
ISU UI
UNI
T R/B E
Would adding the elements of the rows provide meaningful data? Explain.
Answer: No, the first two elements of a row are in dollars and the third is in numbers of people.
Example 1

12. Analyze Data with Matrices
D. Use the matrix below that includes information on tuition (T), room and board (R/B), and enrollment (E) for three universities.
ISU UI
UNI
T R/B E
Would adding the elements of the third column provide meaningful data? Explain.
Answer: Yes, the sum of the elements of the third column would be the total enrollment of all three schools.
Example 1

13. Execution Degree Score of Difficulty
The matrix displays Karen’s diving scores for her 6 dives at a competition. The total score is found by multiplying the degree of difficulty by the execution score.
Dive 1
Dive 2
Dive 3
Dive 4
Dive 5
Dive 6
Execution Degree Score of Difficulty
Example 1

14. A. Find the average of the elements in column 1, and interpret the results.
A. The average number of dives is 8.36.
B. The average score for the 6 dives is 8.36.
C. The average execution for the 6 dives is 8.36.
D. The average degree of difficulty for the 6 dives is 8.36. _
Example 1

15. B. The matrix displays Karen’s diving scores for her 6 dives at a competition. The total score is found by multiplying the degree of difficulty by the execution score. Which dive’s total is the highest?
A. dive 1
B. dive 3
C. dive 4
D. dive 6
Example 1

16. A. Yes, adding the elements gives the total score.
C. The matrix displays Karen’s diving scores for her 6 dives at a competition. The total score is found by multiplying the degree of difficulty by the execution score. Would adding the elements of the rows provide meaningful data? Explain.
A. Yes, adding the elements gives the total score.
B. No, the last element of the row is the product of the first and second elements in the row.
Example 1

17. D. The matrix displays Karen’s diving scores for her 6 dives at a competition. The total score is found by multiplying the degree of difficulty by the execution score. Would finding the average of the last column provide meaningful data?
A. Yes, the average of the last column would be the average score for all 6 dives in the competition.
B. No, each score has a different degree of difficulty, so you can’t find the average.
Example 1

18. Concept

19. Add corresponding elements.
Add and Subtract Matrices
Substitution
Add corresponding elements.
Simplify.
Answer:
Example 2

20. Add and Subtract Matrices–
Answer: Since the dimensions of A are 2 × 3 and the dimensions of B are 2 × 2, these matrices cannot be subtracted.
Example 2

21. A. B. C. D.
Example 2

22. A. B. C. D.
Example 2

23. Concept

24. Multiply a Matrix by a Scalar
Substitution
Example 3

25. Multiply each element by 2.
Multiply a Matrix by a Scalar
Multiply each element by 2.
Simplify.
Answer:
Example 3

26. A. B.
C. D.
Example 3

27. Concept

28. Perform the scalar multiplication first. Then subtract the matrices.
Multi-Step Operations
Perform the scalar multiplication first. Then subtract the matrices.
4A – 3B
Substitution
Distribute the scalars in each matrix.
Example 4

29. Subtract corresponding elements.
Multi-Step Operations
Multiply.
Subtract corresponding elements.
Simplify.
Answer:
Example 4

30. A. B. C. D.
Example 4

31. Use Multi-Step Operations with Matrices
BUSINESS A small company makes unfinished desks and cabinets. Each item requires different amounts of hardware as shown in the matrices.
DESK
Short
Long
Nails
Screws
CABINET
The company has orders for 3 desks and 4 cabinets. Express the company’s total needs for hardware in a single matrix.
Example 5

32. Write matrices. Multiply scalars. Add matrices. Short Long Nails
Use Multi-Step Operations with Matrices
Write matrices.
Multiply scalars.
Add matrices.
Short
Long
Nails
Screws
Answer:
Example 5

33. Blue Yellow Green A. B. C. D. Course A Course B Course C
Miniature golf course A has 50 blue golf balls, 100 yellow golf balls, and 50 green golf balls. Miniature golf course B has 150 blue golf balls, 100 yellow golf balls, and 25 green golf balls. Miniature golf course C has 40 blue golf balls, 70 yellow golf balls, and 80 green golf balls. Express the total number of each color golf ball in a single matrix.
Blue
Yellow
Green
A. B.
C. D.
Course A
Course B
Course C
Example 5

34. End of the Lesson