SOLUTION: Solve for X. Assume X is a 2×2 matrix. Do not use decimal numbers in your answer. If there are fractions, leave them unevaluated. [8, 6] [-4, 4] - X[-7, -8] [3 , -6] = I

Algebra ->  Matrices-and-determiminant -> SOLUTION: Solve for X. Assume X is a 2×2 matrix. Do not use decimal numbers in your answer. If there are fractions, leave them unevaluated. [8, 6] [-4, 4] - X[-7, -8] [3 , -6] = I      Log On


   



Question 1159576: Solve for X. Assume X is a 2×2 matrix. Do not use decimal numbers in your answer. If there are fractions, leave them unevaluated.
[8, 6]
[-4, 4]
-
X[-7, -8]
[3 , -6]
=
I

Answer by ikleyn(52925) About Me  (Show Source):
You can put this solution on YOUR website!
.

You are given a matrix equation

    B - X*A = I.

where B, A and I are given  2x2-matrices.


Re-write it in the form

    X*A = C,       (1)

where  C = B - I.



Now, the matrix A is non-degenerated (since its determinant is not zero).


Therefore, the inverse matrix  A%5E%28-1%29  does exist.

Calculate the inverse matrix  A%5E%28-1%29,  using your knowledge of linear/(matrix) algebra.


Then multiply equation (1)  by the matrix  A%5E%28-1%29  from the right side.


You will get then the solution 

    X = C%2AA%5E%28-1%29.

Having these instructions, complete your job on your own.

If it is allowed to you to use a calculator for matrix calculations, you can use it . . .