When Kramer rule is used, what is the solution of the system of equations when d = 0? I want to know how to deduce rank less than n from D = 0

When Kramer rule is used, what is the solution of the system of equations when d = 0? I want to know how to deduce rank less than n from D = 0

X1=2,X2=-2,X3=-3,X4=-1

Ask why a has a solution when a has a value, and find the solution x2-x3 + X4 = a X1 + 3x2 + 2x3 + X4 = 1 X1 + 2x2 + 3x3 when a has a solution
The last constraint is
x1+2x2+3x3=3

A = - 2, written in the form of augmented matrix, the first line is 1.322.11, the second line is 1.233.03, the third line is 0,1, - 1,1, a, the second line minus, the third line becomes 0-11-12, the third line and this line add to become 0.000a + 2, when there is a solution, a + 2 = 0, a = - 2

Using inverse matrix to solve the equation x1-x2 + X3 = 1, - 2x1-x2-2x3 = 3,4x1 + 3x2 + 3x3 = - 1

Find the inverse matrix 1 - 1 1 1 0 1 0 0 1 2 1 - 2 - 1 - 2 0 1 =, 0 1 1 1 - 2 / 3 - 1 / 3 0 4 3 0 1 0 1 - 2 / 3 - 7 / 3 - 1, the result is 1 21 - 1 - 4 - 2 / 3 - 1 / 3 0 * - 1 = 1, get X1 = - 4, X2 = 1, X3 = 4 - 2 / 3 - 7 / 3 - 1 - 1 4

The ratio of velocity is V1: V2: V3 = 1:2:3, when the ratio of time T1: T2: T3 =?

V1:V2:V3=1:2:3=k
V1=k
V2=2k
V3=3k
T1=S/V1=S/K
T2=S/V2=S/2K
T3=S/V3=S/3K
T1:T2:T3=S/K:S/2K:S/3K=1:1/2:1/3 =3:2:1