Matrix Equations Set Up

Dimensions?

• a

• b

• c

• d

What would be the dimensions (output) of AB?

• undefined

• 2 X 2

• 3 X 2

• 3 X 3

find: B*A

• 47     30
  9     5

• 17     15
  42     35

• 10     25
  7     1

• not possible because rows do not match columns

What is the correct order of solving systems of equations?

• Set up the matrix. 2. Find the determinant. 3. Multiply the determinant by the solution matrix.

• Set up the matrix. 2. Multiply [A] *[B] - (the solution matrix) 3. Find the inverse of that answer.

• Set up the matrix. 2. Find the inverse of [A]. 3. Multiply the inverse by the solution matrix.

• Use a calculator.

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

Solve the system.  Write the matrix equation on your own paper.
5x + 8y = -12
3x + 5y = -7

• (1, -10)

• No solution

• (-4, 1)

• (1, 10)

• 
• 
• 
• 

Are these matrices inverses of each other?

• Yes

• No

• Unable to Determine

What must be true in order to MULTIPLY two matrices?

• They must be square.

• The dimensions must be equal.

• The determinant can't equal 0.

• The #of columns of the 1st must equal the # of rows of the 2nd.

In Matrix R (pictured) what is the value of element R_3,2

• 8

• 9.01

• 6

• 1