Q.

Let αβγ=45; α,β,γR. If x(α,1,2)+y(1,β,2)+z(2,3,γ)=(0,0,0) for some x,y,zR,xyz0, then 6α+4β+γ is equal to _______.            [2024]


Ans.

(55)

We have, x(α,1,2)+y(1,β,2)+z(2,3,γ)=(0,0,0)

αx+y+2z=0; x+βy+3z=0; 2x+2y+γz=0

Since, xyz0 so the system of equations has non-trivial solution.

Now, |α121β322γ|=0

α(βγ-6)-1(γ-6)+2(2-2β)=0

αβγ-6α-γ+6+4-4β=0

45+10-6α-γ-4β=06α+4β+γ=55