find the inverse of matirx m= 2 1

Question

-1 3
is it 3 -1
1 2
and how dod i find the value of and a y for which ma is x and y

Answer 1

If you multiply
2 1
-1 3 by

3 -1
1 2 you get

7 0
0 7

So divide each of the entries in your inverse matrix by 7

in general for the inverse of
a b
c d

you would have

d -b
-c a with each term divided by (ad-bc)

1.