Basic Operations with Matrices

You can multiply a 2X3 matrix by which matrix?

• 2X2

• 2X12

• 3X12

• 2X3

Find the product of the two matrices.

• 1   2
  6   -8

• -3   -5
  -5   -11

• -2     8
  -6   -12

• 2  -3
  5   -2

a₂₃ + a₁₂ - a₃₁ + a₄₃?

• -2

• -1

• -3

• 0

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 )

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  

Find A-B

• -3     1
  7     -1

• 1     0
  1     -4

• -4       0
  6     -1

• not possible because rows do not match columns

Find B-A

• -4     0
  6     -1

• 1     0
  1     -4

• 4       0
  -6     1

• not possible because rows do not match columns

Find the values of w,x, y and z.

• 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

Add

• 11    8
  -4     2

• 3     2
  -6    -6

• -3    2
  -4    -6

• 10    8
  -6    2

What are the dimensions of this matrix?

• 3x1

• 1x3

• 3x3

• 1x1