JEE Main 2021MathematicsDeterminantsEasyMCQ

JEE Main 2021 — Determinants Question with Solution

JEE Main 2021 (20 Jul Shift 2)

Question

The value of k∈R, for which the following system of linear equations

3x-y+4z=3

x+2y-3z=-2

6x+5y+kz=-3

has infinitely many solutions, is:

Choose an option

Show full solutionCorrect option: B
Correct answer
B-5

Step-by-step explanation

We have,

3x-y+4z=3

x+2y-3z=-2

6x+5y+kz=-3

For infinitely many solutions,

A=0

⇒3-1412-365 k=0

⇒3(2k+15)+1k+18+45-12=0

⇒3(2k+15)+k+18-28=0

⇒7k+35=0

⇒k=-5

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About this question

This is a previous-year question from JEE Main 2021, 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.