Verified Solution • 2025–26 Session
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QJEEM20Mab1be: JEE Main 2020 Mathematics - Class 12 JEEM20Mab1be Solution: If the system of linear equations x + y + 3z = 0 x + 3y + k 2 z …
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 + is equal to :
x + y + 3z = 0
x + 3y + k2z = 0
3x + y + 3z = 0
has a non-zero solution (x, y, z) for some k
Multiple Choice Options
- A 9
- B 3
- C -9
- D -3
Step-by-Step Verified Solution
x + y + 3z = 0 .....(i)
x + 3y + k2z = 0 .........(ii)
3x + y + 3z = 0 ......(iii)
= 0
9 + 3 + 3k2 – 27 – k2 – 3 = 0
k2 = 9
Perform (i) – (iii),
–2x = 0 x = 0
Now from (i), y + 3z = 0
x + = -3
x + 3y + k2z = 0 .........(ii)
3x + y + 3z = 0 ......(iii)
Perform (i) – (iii),
–2x = 0
Now from (i), y + 3z = 0