The system of equations
−2x+y+z=a
x−2y+z=b
x+y−2z=c
has
No solution if a+b+c≠0
Unique solution if a+b+c=0
Infinite number of solutions if a+b+c=0
none of these
When we add three equations, we get 0=a+b+c .
Thus, the system does not have a solution if a+b+c≠0 .
If a+b+c=0 , the system has infinite number of solutions given by
x=13(3k−2a−b)
y=13(3k−a−2b)
z=k
Wherek∈C .