Matrices

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

What is a₂₃

• 14

• 4

• 1

• 3

Which sums can NOT be made from the following matrices ?

• A+A

• A+C

• B+D

• C+C

If A is a 2 × 3 matrix, and B is a 3 × 4 matrix, how many columns does AB have?

• 2

• 3

• 4

• AB is not defined

BA=

• Undefined

• 
• 
• 

• 
• 
• 
• 

• 
• undefined/not possible

• 
• 

• 
• No solution

• 
• 

Matrices can be multiplied only...

• if the row of the first matrix is equal to the column of the second matrix.

• if the column of the first matrix is equal to the column of the second matrix.

• if the column of the first matrix is equal to the row of the second matrix.

• if the row of the first matrix is equal to the row of the second matrix.

The matrix A - B is

• 
• 
• 
•