A singular matrix has determinant equal to 0.
For matrix A=[x234]:
det(A)=(x)(4)−(3)(2)=0
4x−6=0
4x=6
x=46=1.5
For matrix B=[2y33]:
det(B)=(2)(3)−(3)(y)=0
6−3y=0
3y=6
y=2
For matrix C=[z812]:
det(C)=(z)(2)−(1)(8)=0
2z−8=0
2z=8
z=4
With x=1.5, y=2, and z=4:
(A) x>y: Is 1.5>2? False
(B) y>z: Is 2>4? False
(C) z>x: Is 4>1.5? True
(D) x=y=z: Are 1.5, 2, and 4 all different? True
Both (C) and (D) are correct.