DeterminantHard

Question

The system of linear equations x + y - z = 6, x + 2y - 3z = 14 and 2x + 5y - λz = 9 (λ ∈ R) has a unique solution if

Options

A.λ = 8
B.λ = 8
C.λ = 7
D.λ ≠ 7

Solution

Here ᐃ = system has unique solution if ᐃ ≠ 0 and at least one of ᐃx, ᐃy, ᐃz is non-zero.
ᐃ = 1(-2λ + 15) - 1(- λ + 6) - 1(5 - 4) ≠ 0 ⇒ - 2λ + 15 +λl - 6 - 1 ≠ 0
⇒  - l + 8 ≠ 0 ⇒  λ ≠ 8

Create a free account to view solution

View Solution Free
Topic: Determinant·Practice all Determinant questions

More Determinant Questions