Question

Let
A = [2 -4;
2 5]
Find A^{-1} and use it to solve
AX=B
where
B=[3;
2]
X=[x{1};
x{2}]
where x_{1}=?? and x_{2}=?? .

Answer 1

say A=[a b ;
c d]
then the inverse of A is B=[d -b;
-c a]/(ad-bc);
all the elements are divided by determinant of A