Matrices Practice

In Matrix R (pictured) what entry is in the second row, third column?

• 8

• 9.01

• 6

• 1

What must be true in order to ADD two matrices?

• They must be square.

• The dimensions must be the same.

• The determinant can't equal 0.

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

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 are the dimensions of this matrix?

• 2 x 3

• 3 x 2

• 6 x 1

• 1 x 6

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

• 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

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• 
• 
• 

Find 3B - 2A

• [22 25]

  [17 3]

• [14 5]

  [-11 3]

• [-14 5]

  [11 -3]

• none of these

Find 2A-3B

• -3 1

  7 -1

• 1 0

  1 -4

• -4 0

  6 -1

• -14 -5

  11 -3

Find 2B-5A

• 
• 
• 
• 

Dimensions?

• a

• b

• c

• d