Mathematics · Determinants

JEE Main 2024 — 6 April, Shift 1 — Question 21

Let αβγ=45;α,β,γ∈\alpha \beta \gamma=45 ; \alpha, \beta, \gamma \in R. If x(α,1,2)+y(1,β,2)x(\alpha, 1,2)+y(1, \beta, 2) +z(2,3,γ)=(0,0,0)+z(2,3, \gamma)=(0,0,0) for some x,y,z∈R,xyz≠x, y, z \in R, x y z \neq 0 , then 6α+4β+γ6 \alpha+4 \beta+\gamma is equal to \qquad

Answer: 55

Numerical answer — enter this value.

Step-by-step solution

αβγ=45,α,β,γ∈R\alpha \beta \gamma=45, \alpha, \beta, \gamma \in R

x(α,1,2)+y(1,β,2)+z(2,3,γ)=(0,0,0)x(\alpha, 1,2)+y(1, \beta, 2)+z(2,3, \gamma)=(0,0,0)

x,y,z∈R,xyz≠0x, y, z \in R, x y z \neq 0,

αx+y+2z=0\alpha x+y+2 z=0

x+βy+3z=0x+\beta y+3 z=0

2x+2y+γz=02 x+2 y+\gamma z=0

xyz≠0⇒\mathrm{xyz} \neq 0 \Rightarrow non-trivial

\left| \begin{array}{*{35}{l}}\alpha & 1 & 2 \\1 & \beta & 3 \\2 & 2 & \gamma \\\end{array} \right|=0

⇒α(βγ−6)−1(γ−6)+2(2−2β)=0\Rightarrow \alpha(\beta \gamma-6)-1(\gamma-6)+2(2-2 \beta)=0

⇒αβγ−6α−γ+6+4−4β=0\Rightarrow \alpha \beta \gamma-6 \alpha-\gamma+6+4-4 \beta=0

⇒6α+4β+γ=55\Rightarrow 6 \alpha+4 \beta+\gamma=55

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Determinants
Topic
Consistency of homogeneous sysytem
Let α β γ=45 ; α, β, γ in R. If x(α, 1,2)+y(1, β, 2) +z(2,3… | JEE Main 2024 PYQ with Solution · DhiX AI