Verified Solution • 2025–26 Session moderate

QJEEM24Ma10de: JEE Main 2024 Mathematics - Class 12 JEEM24Ma10de Solution: Let . If for some , then is equal to _________.

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

Step-by-Step Verified Solution

Given that αβγ=45\alpha \beta \gamma = 45 and α,β,γ∈R\alpha, \beta, \gamma \in \mathbb{R} , consider the equation 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) for some x,y,z∈Rx, y, z \in \mathbb{R} where xyz≠0x y z \neq 0 . To find the value of 6α+4β+γ6 \alpha + 4 \beta + \gamma , follow these steps:

  1. Express the given equation in matrix form:

amp;αx+y+2z=0amp;x+βy+3z=0amp;2x+2y+γz=0\begin{aligned} & \alpha x + y + 2 z = 0 \\ & x + \beta y + 3 z = 0 \\ & 2 x + 2 y + \gamma z = 0 \end{aligned}

  1. Since x,y,z≠0x, y, z \neq 0 , the determinant of the coefficients matrix must be zero:

∣αamp;1amp;21amp;βamp;32amp;2amp;γ∣=0\left|\begin{array}{ccc} \alpha & 1 & 2 \\ 1 & \beta & 3 \\ 2 & 2 & \gamma \end{array}\right| = 0

  1. Calculate the determinant of the matrix:

αβγ−6α−4β−γ+10=0\alpha \beta \gamma - 6 \alpha - 4 \beta - \gamma + 10 = 0

  1. Given αβγ=45\alpha \beta \gamma = 45 , substitute this value into the equation:

45−6α−4β−γ+10=045 - 6 \alpha - 4 \beta - \gamma + 10 = 0

  1. Simplify the equation:

45+10=6α+4β+γ45 + 10 = 6 \alpha + 4 \beta + \gamma

  1. Thus,

6α+4β+γ=556 \alpha + 4 \beta + \gamma = 55

So, the value of 6α+4β+γ6 \alpha + 4 \beta + \gamma is 55.

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