If A, B, and C are n x n invertible matrices, does the equation C^-1 (A+X)B^-1= In have a solution X? If so, find it.
Select the correct choice below:
A. The solution is X = _______
B. There is no solution

Respuesta :

Supposing the right hand side is another [tex]n\times n[/tex] matrix [tex]M[/tex], we have

[tex]C^{-1}(A+X)B^{-1}=M[/tex]

[tex](CC^{-1})(A+X)B^{-1}=CM[/tex]

[tex](A+X)B^{-1}=CM[/tex]

[tex](A+X)(B^{-1}B)=CMB[/tex]

[tex]A+X=CMB[/tex]

[tex]X=CMB-A[/tex]

Invertible matrices are matrices whose inverse exist. The solution of the given matrix equation exists and is: [tex]X = CB - A[/tex]

What are invertible matrices?

An invertible matrix is a matrix whose inverse matrix exists.

If A is a matrix and A⁻¹ is its inverse, then

[tex]A \tiems A^{-1} = I[/tex]

where I is identity matrix of same shape as A was.

The given matrix equation is solved as:

[tex]C^{-1} (A+X) B^{-1} = I_n\\\\\text{Multiplying C matrix on left of both sides, and B on right of both sides}\\\\CC^{-1} (A+X) B^{-1} B = CI_nB\\I_n \times (A+X) \times I_n = CI_nB\\A + X = CB \text{\:\:\:(Property of identity matrix multipication)}\\\\\text{Adding -A matrix on both the sides}\\\\A + X + (-A) = CB + (-A)\\X = CB - A[/tex]

Thus, the solution of the given matrix equation exists and is: [tex]X = CB - A[/tex]

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