The simultaneous equations
2x + ay + z = 20
x + 3y + 4z = b
x + 2y + 3z = c
has unique solution then what is the value of a, b and c respectively?
1
a ≠ ± 1, b and c can be any value
2
a ≠ ± 1, b ≠ 0, c ≠ 1
3
a ≠ -1, b and c can be any value
4
a, b and c can be any value