Find det(A) for the following matrices A over R: (I) A = 41) (II) A = (21 _4) (III) A = (xY )• —x State whether each matrix is invertible or not, and find the inverse if it is. 2. Find the...

Find det(A) for the following matrices A over R: (I) A = 41) (II) A = (21 _4)
(III) A = (xY )• —x
State whether each matrix is invertible or not, and find the inverse if it is.
2. Find the determinants of the following matrices:
(I) (2 —3 2 7 1 4 1 2 —1 (ii) (x y z x y 2 y x