Which pair of matrices are inverses of each another?

if we put symbols for the numbers in the first matrix 
[tex] \left[\begin{array}{ccc}a&b\\c&d\\\end{array}\right] [/tex] 
to find the inverse of the first matrix
first we need to find the determinant (D)
D = ad - bc
a = 2, b = 3 , c = 6 and d = 8
D = 2x8 - 3x6
    = 16 - 18
    = -2
then to find the inverse we have to exchange a and d and also multiply b and c by -1
and divide all the terms in the matrix by determinant 
inverse matrix is then 
[tex] \left[\begin{array}{ccc} \frac{8}{-2} & \frac{-3}{-2} \\ \frac{-6}{-2} & \frac{2}{-2} \\\end{array}\right] [/tex] 
simplified matrix, the answer of inverse matrix is 
[tex] \left[\begin{array}{ccc}-4& \frac{3}{2} \\3&-1\\\end{array}\right] [/tex]