The question states determine whether the given matrix is invertible. If it is calculate the inverse:
Ive tried it many times, but cant seem to get anywhere near what i should be getting.. Can anyone help?
The determinant of the matrix is -9, so the matrix is invertible.
To calculate the inverse, use Gauss elimination (Gaussian elimination - Wikipedia, the free encyclopedia) or Analytic solution (Invertible matrix - Wikipedia, the free encyclopedia)