Matrices Addition, Subtraction and Multiplication

How many rows does this matrix have?

• 2

• 3

• 6

• 4

Dimensions?

• a

• b

• c

• d

• A
• B
• C
• D

What do w, x, y and z equal in this matrix subtraction?

• w = 13, x = 4, y = 7, z = 23

• w = 13, x = -4, y = 11, z = 23

• w = 13, x = 4, y = 11, z = 23

• w = 13, x = 4, y = 11, z = 17

What must be true in order to ADD two matrices?

• They must be square.

• The dimensions must be equal.

• The determinant can't equal 0.

• The column of the 1st must equal the row of the 2nd.

• A
• B
• C
• D

What do a, b, c and d equal in this matrix addition?

• a = -1, b = 10, c = 7, d = -11

• a = -1, b = 10, c = -11, d = 7

• a = 10, b = -1, c = 7 , d = -11 

• a = 10, b = -1, c = -11, d = 7

Subtract

• 3    -8
  0   -1

• 3   -4
  8  -13

• -3   8
  0    1

• 3   -8
  -8    1

Find A+B

• 8     10
  8      1 

• 12     25
  7     1

• 10     30
  0     1

• can't add two together because the rows dont match columns

What do m, n, p and q equal in this scalar matrix multiplication?

• m=8, n=9, p=-4, q=4 

• m=15, n = -45, p=20, q=-5

• m=20, n=-5, p=15, q=-45

• m=-5, n=20, p=-45, q=15