1. ## Matrices Multiplication

2. Originally Posted by positiveion
Have you been taught how to do matrix multiplication? Matrix multiplication - Wikipedia, the free encyclopedia

3. I've been taught but not with unknown variables.. :S

I'm not sure how to do it, when I multiply out the first part its
-a^2+2a-4
.. do I just put that into the top right hand corner of the matrice?

4. Originally Posted by positiveion
I've been taught but not with unknown variables.. :S

I'm not sure how to do it, when I multiply out the first part its
-a^2+2a-4
.. do I just put that into the top right hand corner of the matrice?
Top left corner, actually.

You do the multiplication in the usual way.

5. Is this the correct answer, then?

6. Originally Posted by positiveion
Is this the correct answer, then?
Bottom left entry ..... the 2a^2 should be -2a^2.

7. Oh okay!
Thank you!