Matrix algebra - matrix equation

[Bitter]

A=(5, 4) I (1, 0)
(4,6) (0,1)

Those are matrix by the way.

How do I show A^2=11A-18I? I know I'm overlooking something, but i don't know what. Any tips would be helpful

 

[Bitter]

ah I am sorry, I meant to put this in the question section, please move!

 

[radou]

Do you know how to multiply matrices? You may want to look at this link: http://www.purplemath.com/modules/mtrxmult.htm" .

 

[matt grime]

Let me ask you this.

Let x=3. How do you show that x^2=2x+3?