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…

If the system of equations

kx+y+2z=1

3x-y-2z=2

-2x-2y-4z=3

has infinitely many solutions, then k is equal to ______ .

Solution

If the system of equations

P1: kx+y+2z=1

P2: 3x-y-2z=2

P3: -2x-2y-4z=3

Which are equivalent to equations of planes.

We observe 5P2-P1=3P3

So, 15-K=-6

 K=21

Asked in: JEE Main 2021 (25 Feb Shift 1)

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