7.4 Matrices Quiz REVIEW

Add

• 11 8

  -4 2

• 3 2

  -6 -6

• -3 2

  -4 -6

• 11 8

  -6 -2

What must be true in order to ADD or SUBTRACT 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.

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

Subtract

• 3    -8
  0   -1
• 3   -4
  8  -13
• -3   8
  0    1
• 3   -8
  -8    1

Perform the indicated operation

• 
• 
• 
• 
• not possible

Perform the indicated operation

• 
• 
• 
• 
• not possible

What are the dimensions of this matrix?

• 2 x 3
• 3 x 2
• 6 x 1
• 1 x 6

Multiply

• 20     15    -10
  30     -5         0
• -20      15     -10
  30     -5          0
• 1        8       3
  11     4        5
• 20     -15     10
  -30         5        0  

How many columns are in a 5 x 4 matrix?

• 5
• 4
• 20
• 9

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

• 8
• 9.01
• 6
• 1