Need help with multiplication and matrix problem?

Question

use the fact that :

*** A=|a b|

|c d|,

*** A^-1= 1/ad-bc|d -b|

|-c a|

to find the inverse of the matrix.

***Check that AA^-1 = I (base2) and A^-1A=I (base2)

A= |6 -3|

|-2 1|

Answer 1

There is no inverse. Notice what happens when you try to find 1/(ad-bc). You get

1/[ 6(1) - (-3)(-2) ] = 1/( 6 - 6) = 1/0

Which is implossible...

Answer 2

No inverse.  

Answer 3

simple, since the 1/ad-bc is a scalar you can re arrange to:

AA^-1 =1/ad-bc * |a b ; c d| * |d -b ; -c a|

Just put in the numbers and evaluate.

the same goes for the second part.

you should be left with the identity matrix | 1 0 ; 0 1|

Note i have used ; to denote a new line in the matrix