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Question
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Solution
Given:α, β, γ are in A.P.
Now,
`Delta=1/2|(x-3,x-4,x-alpha),(2x-4,2x-6,2x-2beta),(x-1,x-2,x-gamma)|` `["Applying" R_2->2R_2]`
`Delta=1/2|(x-3,x-4,x-alpha),(0,0,-2beta+alpha+gamma),(x-1,x-2,x-gamma)|` `[because 2beta=alpha+gamma]` `["Applying" R_2->R_2-(R_1+R_3)]`
`Delta=1/2|(x-3,x-4,x-alpha),(0,0,0),(x-1,x-2,x-gamma)|`
Δ = 0
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