2. Lesson 12.1 – Adding and Subtracting Matrices Take notes in your notebook. Work the problems in your notebook BEFORE advancing to the solutions.

3.  A matrix is a rectangular arrangement of numbers into rows and columns. 4 -2 9 0 3 -5 This is a 2 by 3 Matrix.

4. 2 Rows and 3 Columns 4 -2 9 0 3 -5

5.  Matrix - a rectangular array of variables or numbers in horizontal rows and vertical columns enclosed in brackets.  Element - each value in a matrix; either a number or a constant.  Dimension - number of rows by number of columns of a matrix.  **A matrix is named by its dimensions.

6. Dimensions: 3x2 Dimensions: 4x1 Dimensions: 2x4

7. 3 x 3 3 x 5 2 x 2 4 x 1 1 x 4 (aka: square matrix) (aka: row matrix) (or square matrix) (aka: column matrix)

8. Column Matrix – a matrix with only one column. Row Matrix – a matrix with only one row. Square Matrix – a matrix that has the same number of rows and columns.

9. 1.) -3 -2 6 -8 5 -7 -9 6 Add the corresponding elements of each matrix.

10. To add two matrices, they must have the same dimensions. To add, you simply add corresponding elements. Answer Matrix Working matrix

11. 4 -2 9-1 0 0 3 -5 3 7 Matrices can only be added if they have the same # of rows & columns 2 x 32 x 2

12. 7 = = 745 075 7 Working matrix Solution matrix

13.  1.) -3 -2 6 -8  5 -7 -9 6 Subtract the corresponding elements of each matrix.

14. To subtract two matrices, they must have the same dimensions. You simply subtract corresponding elements. Working matrix Solution matrix

15. = 5-2 -4-13-8 8-30-(-1)-7-1 1-(-4) 2-0 0-7 = 2-5 5 1 -8 53-7 Working matrixSolution matrix

16. 1.) -3 -2 6 -8 5 -7 -9 6 2.) 3 -7 4 -3 7 -1 7 8 3.) -5 7 -6 5 -3 -9 -1 7

17. 1.) -3 -2 6 -8 5 -7 -9 6 2.) 3 -7 4 -3 7 -1 7 8 3.) -5 7 -6 5 -3 -9 -1 7 3 -10 -4 -1 7 -10 14 7 1 2 -2 -16

18. 4.) 0 -3 -6 0 -1 4 3 1 5.) 1 14 -3 1 1 7 0 6.) -5 7 5 -7 -3 -9 3 9

19. 4.) 0 -3 -6 0 6 -3 -1 4 3 1 -4 -2 5.) 1 14 -3 -3 4 1 1 7 0 -6 1 6.) -5 7 5 -7 0 0 -3 -9 3 9 0 0

20.  Read Lesson 12.1 “Adding and Subtracting Matrices” in your textbook and review the Power Point lesson again.  Complete the 12.1 Vocabulary Worksheet  Review and complete the 12.1 Reteaching Worksheet

21. In your textbook:  Lesson 12.1/ 7- 17odd, 19-29

22. Jim, Mario and Mike are married to Shana, Kelly and Lisa. Mario is Kelly’s brother and lives in Florida with his wife. Mike is shorter than Lisa’s husband. Mike works at a bank. Shana and her husband live in Kentucky. Kelly and her husband work in a candy store. Who is married to whom? Shana Kelly Lisa Jim MarioMike X X X OX XO XO