JEE Main 2020MathematicsDeterminantsMediumMCQ

JEE Main 2020 — Determinants Question with Solution

JEE Main 2020 (05 Sep Shift 2)

Question

If the system of linear equations
x+y+3z=0
x+3y+k2z=0
3x+y+3z=0
has a non-zero solution (x, y, z) for some k∈R, then x+yz is equal to :

Choose an option

Show full solutionCorrect option: A
Correct answer
A-3

Step-by-step explanation

So D=0→11313k2313=0  ⇒  k2=9

x+y+3 z=0

x+3 y+9 z=0

3 x+y+3 z=0

(1)-(3)
x=0⇒  y+3z=0

⇒yz=-3
so, x+yz=-3

 

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About this question

This is a previous-year question from JEE Main 2020, covering the Determinants chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.