jee-main 2020 Q60
Linear System Existence and Uniqueness via Determinant
If the system of linear equations $$\begin{aligned}
& 2x + 2ay + az = 0 \\
& 2x + 3by + bz = 0 \\
& 2x + 4cy + cz = 0
\end{aligned}$$ where $a, b, c \in R$ are non-zero and distinct; has a non-zero solution, then
(1) $\frac { 1 } { a } , \frac { 1 } { b } , \frac { 1 } { c }$ are in $A.P$.
(2) $a, b, c$ are in $G.P$.
(3) $a + b + c = 0$
(4) $a, b, c$ are in $A.P$.