Matrix Operations Opener

How many columns are in a 5 x 4 matrix?

• 5
• 4
• 20
• 9

What are the dimensions of this matrix?

• 2 x 3
• 3 x 2
• 6 x 1
• 1 x 6

In Matrix R (pictured) what element is r₂₃?

• 8

• 9.01

• 6

• 1

Add

• 11    8
  -4     2
• 3     2
  -6    -6
• -3    2
  -4    -6
• 10    8
  -6    2

Subtract

• -5
  -8
  3
  10
• -9
  8
  3
  2
• 5
  -8
  3
  10
• -5
  8
  3
  2

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  

Can the operation be performed?

• Yes

• No

• Sometimes

• only Ms. Jones knows

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• undefined

• ( 3 x 1 )

• ( 1 x 2 )

• ( 3 x 2 )

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• ( 3 x 1 )

• ( 3 x 2 )

• ( 3 x 3 )

• undefined

find: B*A

• 47     30
  9     5
• 17     15
  42     35
• 10     25
  7     1
• not possible because rows do not match columns