Question 347502
Given a 2x2 square matrix
[a    b]
[c    d]
the inverse is found by
{{{1/(ad - bc)}}} times
[d   -b]
[-c   a]
so your inverse is
(-1/3) times 
[-3   -5]
[-6   -9]
OR
(1/3) times 
[3   5]
[6   9]
OR
[1   5/3]
[2    3]