JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant
If the system of equations \(k x+y+2 z=1\) ; \(3 x-y-2 z=2\) ; \(-2 x-2 y-4 z=3\) has infinitely many solutions, then \(k\) is equal to ..........
- A \(21\)
- B \(42\)
- C \(14\)
- D \(28\)
Answer & Solution
Correct Answer
(A) \(21\)
Step-by-step Solution
Detailed explanation
We observe \(5 P _{2}- P _{1}=3 P _{3}\) So, \(15- K =-6\) \(\Rightarrow K =21\)
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