Skip to main contentSkip to solution

Consider the system of equation x+y+3z=8x+y+3z=8, 2x+y+bz=242x+y+bz=24, x+ay+3z=10x+ay+3z=10, then which of the following statements are True?

(A) The system of equations has a unique solution if a=2,b=3a=2, b=3

(B) The system of equations is inconsistent if a=1,b∈Ra=1, b \in R be any real number.

(C) The system of equations is inconsistent if a≠1a \neq 1, and b≠6b \neq 6

(D) The system of equations has a unique solution if a=4a=4 and b=3b=3.

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 3

The coefficient determinant is Δ=(a−1)(6−b)\Delta = (a-1)(6-b), so the solution is unique exactly when a≠1a\neq 1 and b≠6b\neq 6.

(A) and (D) satisfy this. If a=1a=1, equations 1 and 3 read x+y+3z=8x+y+3z=8 and x+y+3z=10x+y+3z=10, a contradiction, so (B) holds for every bb. (C) is false since those conditions give a unique solution.

Keyboard Shortcuts

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