JEE Main202324 Jan 2023Evening ShiftMathematicsDeterminantsActual
If the system of equations x + 2 y + 3 z = 3 , 4 x + 3 y - 4 z = 4 and 8 x + 4 y - λ z = 9 + μ has infinitely many solutions, then the ordered pair λ , μ is equal to
Options
- A72 5 , 21 5
- B- 72 5 , - 21 5
- C72 5 , - 21 5
- D- 72 5 , 21 5
Correct answer
C. 72 5 , - 21 5
Step-by-step solution
Given, The system of equations x + 2 y + 3 z = 3   . . . . . . 1 4 x + 3 y - 4 z = 4   . . . . . . . . . 2 8 x + 4 y - λ z = 9 + μ   . . . . . 3 Now using the operation, equation 1 × 4 - 2 we get, 5 y + 16 z = 8   . . . . . . . . 4 Now using the operation, equation 2 × 2 - 3 we get, 2 y + λ - 8 z = - 1 - μ   . . . . . . . . 5 Now using the operation, equation 4 × 2 - 3 × 5 we get, 72 - 5 λ z = 21 + 5 μ Now given system of equation has infini