Let me show you how I did it,
A is 3 rows 2 colums.
Matrix (vector) b is 2 rows 1 colums
X is 1 row 2 coloms.
For some numbers x and y.
Thus, by equality,
Solving the first two equations we have,
y=0 and x=1
That does not solve the third equations.
There there is no such coefficient matrix X.