JEE Main202229 Jun 2022Morning ShiftMathematicsDeterminantsActual
If the system of linear equations 2 x + y - z = 7 x - 3 y + 2 z = 1 x + 4 y + δ z = k , where δ , k ∈ R has infinitely many solutions, then δ + k is equal to
Options
- A- 3
- B3
- C6
- D9
Correct answer
B. 3
Step-by-step solution
For infinitely many solutions, ∆ = 2 1 - 1 1 - 3 2 1 4 δ = 0 ⇒ δ = - 3 and ∆ 1 = 7 1 - 1 1 - 3 2 K 4 - 3 = 0 ⇒ k = 6 ⇒ δ + K = 3