is this an elementary matrix?
1 0
-5 1
if it is can you explain why it is?

Question

is this an elementary matrix?
  1  0
-5  1
if it is can you explain why it is?

anonymous · Answer

It is an elementary matrix. From Wikipedia:

"In mathematics, an elementary matrix is a simple matrix which differs from the identity matrix by one single elementary row operation."

"Elementary Row Operations.

1.    Interchange two rows. 
2.    Multiply a row with a nonzero number. 
3.    Add a row to another one multiplied by a number."

The identity matrix is
1   0
0   1

So if you add the top row, multiplied by -5 to the bottom row you get your matrix. Which makes it an elementary matrix.