Question 54 of 472MediumMCQ
If α=a,β=b,γ=c and αbcaβcabγ=0, then α−aa+β−bb+γ−cγ is equal to :
Solutions · 1
Official solution
\[\left|\[αaabβbccγ\]\right|=0\]
\[\begin{aligned}
& R_1 \rightarrow R_1-R_2, R_2 \rightarrow R_2-R_3 \\
& \Rightarrow\left|\[\begin{array}{|ccccccc|}\alpha-a & b-\beta & 0 \\ 0 & \beta-b & c-\gamma \\ a & b & \gamma\end{array}\end{aligned}\]\right|=0
\]
Take \[\alpha\]-a, \[\beta\]-b, \[\gamma\]-c common from column-1, 2 and 3 respectively
\[\begin{aligned}
& (\alpha-a)(\beta-b)(\gamma-c)\left|\[\begin{array}{|ccccccc|}1 & -1 & 0 \\ 0 & 1 & -1 \\ \frac{a}{\alpha-a} & \frac{b}{\beta-b} & \frac{\gamma}{\gamma-c}\end{array}\end{aligned}\]\right|=0 \\
\& \Rightarrow \frac{\gamma}{\gamma-c}+\frac{b}{\beta-b}+\frac{a}{\alpha-a}=0
\]
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