First swap the upper left and lower right diagonal elements



Change the signs of upper right and lower left diagonal elements



Calculate the determinant of the original matrix, [or the determinant of
either of these, as they all have the same determinant:

(9)(16)-(-8)(3) = 144-(-24) = 144+24 = 168

Divide each term by the value of the determinant



Reduce any fractions that will reduce (they all will)



This method works ONLY for 2x2 matrices.

Edwin