Skip to main contentSkip to solution

If the system of linear equations

x+2y−3z=1x + 2y - 3z = 1

(2p+1)y+z=2(2p+1)y + z = 2

3x+3z=53x + 3z = 5

has a unique solution, then p can not be equal to

Solution

✅ Correct Option: 2

Unique solution requires determinant of coefficient matrix to be non-zero.

det⁡=1⋅[3(2p+1)−0]−2⋅[0−3]−3⋅[0−3(2p+1)]\det = 1 \cdot [3(2p+1) - 0] - 2 \cdot [0 - 3] - 3 \cdot [0 - 3(2p+1)]

=(6p+3)+6+3(6p+3)=24p+18= (6p+3) + 6 + 3(6p+3) = 24p + 18.

For unique solution, 24p+18≠024p + 18 \neq 0, so p≠−34p \neq -\frac{3}{4}.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question