Add Subtract Multiply Matrices

You can multiply a 2X3 matrix by which matrix?

• 2X2

• 2X12

• 3X12

• 2X3

Add

• 11    8
  -4     2

• 3     2
  -6    -6

• -3    2
  -4    -6

• 10    8
  -6    2

In Matrix R (pictured) what element is in the second row, third column?

• 8

• 9.01

• 6

• 1

find: B*A

• 47     30
  9     5

• 17     15
  42     35

• 10     25
  7     1

• not possible because rows do not match columns

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 B-A

• -3     1
  7     -1

• 1     0
  1     -4

• 4       0
  -6     0

• not possible because rows do not match columns

Dimensions?

• a

• b

• c

• d

What is a Matrix?

• An equation of over 5 numbers or symbols 

• A set of numbers in rows and columns

• A method of finding the n^th value of a series

• A complicated number system

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

Add

• 11    8
  -4     2

• 3     2
  -6    -6

• -3    2
  -4    -6

• 10    8
  -6    2