Algebra 2 problem please help!!!?

Question

I am learning about multiplying matrices and don't understand at all.

Here is an example: Tell whether LM or ML are defined. If so, give the dimensions of the product matrices. If not, explain why.

L is any 8x6 matrix

M is any 6x6 matrix

Answer 1

pretty much they are defined if the inner numbers match up

for example

LM = (8 x 6)(6 x 6) so yes the product is defined since the inside numbers are both sixes

ML = (6 x 6)(8 x 6) so no the product is not defined because the inner numbers dont match

EDIT: forgot to give the dimensions

the product adopts the dimension of its first parent (in this case L) for the first number and the the last number of its second parent (M) for the second number

LM = (8 x 6)

ML doesn't have dimensions because the matrices cant be multiplied in that order

Answer 2

You can only multiply matrices if the the inner dimensions are the same

e.g.

(2x3)(3x4) is defined because of the two 3's and the product would be a (2x4) matrix

(3x5)(3x4) is not defined

Now for your problem:

LM=(8x6)(6x6) is defined and answer is an (8x6) matrix

Try the other one yourself.

Hope this helps

Answer 3

L= 8x6

M=6x6

8x6 X  6x6

..            ..    8x6 is the product matrices

LM product  = take first one on L (8) , and last one of M (6)

ML product = 6x8  

okkk