Inverse matrix in block form

Question

I have a 1 shape matrix (X and U are square):

| X Y |
| Z U |

Which is the inverse of the matrix (which I don’t know) (A and D are square):

| A B |
| C D |

I’m trying to get the inverse matrix of "A", from matrix 1, I tried to use "Matrix inversion in block form", but I can only:

• A-1 * B = Y * U^-1
• C * A^-1 = Z * U^-1

It will be possible to find only A^-1 without having to reverse matrix 1?

matinv