# Matrix Problem

1. May 22, 2014

### teme92

1. The problem statement, all variables and given/known data

Find two matrices E and F such that:

EA=
\begin{bmatrix}
2 & 1 & 2\\
0 & 2 & 1\\
0 & 3 & 0\\
\end{bmatrix}

FA=
\begin{bmatrix}
0 & 2 & 1\\
0 & 3 & 0\\
2 & 7 & 2\\
\end{bmatrix}

2. Relevant equations

3. The attempt at a solution

So I know how to get the inverse of a 3x3 matrix and AxA-1=I the identity matrix but I'm not sure how I approach this as I don't know what A is. Can anyone point me in the right direction here? Any help is much appreciated.

2. May 22, 2014

### verty

Is there more to this problem? I think there is not enough information, A could be the identity matrix in which case it is trivial. A must be given for this to make any sense.

3. May 22, 2014

### teme92

Ok I thought something was wrong with it alright. But to get E normally I'd just say:

EAA-1=XA-1

where X is the matrix giving. Is this correct?

4. May 23, 2014

### CAF123

Yes, provided A is in fact invertible.

5. May 23, 2014

### SammyS

Staff Emeritus
Can you see any set of row operations which will transform matrix EA into matrix FA ?

6. May 24, 2014

### SammyS

Staff Emeritus
You may want to look at the determinant of EA and FA .