JEE Main202125 Feb 2021Evening ShiftMathematicsDeterminantsActual
The following system of linear equations 2 x + 3 y + 2 z = 9 3 x + 2 y + 2 z = 9 x - y + 4 z = 8
Options
- Ahas infinitely many solutions
- Bhas a unique solution
- Chas a solution α , β , γ satisfying α + β 2 + γ 3 = 12
- Ddoes not have any solution
Correct answer
B. has a unique solution
Step-by-step solution
2 x + 3 y + 2 z = 9       . . . 1 3 x + 2 y + 2   z = 9     . . . 2 x - y + 4 z = 8       . . . 3 1 - 2 ⇒ - x + y = 0 ⇒ x - y = 0 from 3   4 z = 8 ⇒ z = 2 from 1   2 x + 3 y = 5 ⇒ x = y = 1 ∴ system has unique solution.