JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant
If the system of equations \( 3x+y+4z=3 \), \( 2x+ay-z=-3 \), \( x+2y+z=4 \) has no solution, then the value of a is equal to :
- A 19
- B 4
- C 13
- D 23
Answer & Solution
Correct Answer
(A) 19
Step-by-step Solution
Detailed explanation
for no solution \( \Delta=0 \) \(\left|\begin{array}{ccc}3 & 1 & 4 \\ 2 & \alpha & -1 \\ 1 & 2 & 1\end{array}\right|=0\) \( \Rightarrow3(a+2)+1(-1-2)+4(4-\alpha)=0 \) \( \Rightarrow19-\alpha=0\Rightarrow\boxed{\alpha=19} \) & for \( \alpha=19 \)…
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