Verify Property $1$ for $\Delta=\left|\begin{array}{ccc}2 & -3 & 5 \\ 6 & 0 & 4 \\ 1 & 5 & -7\end{array}\right|$

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Solution Expanding the determinant along first row, we have

$\Delta  = 2\left| {\begin{array}{*{20}{r}}
  0&4 \\ 
  5&{ - 7} 
\end{array}} \right| - ( - 3)\left| {\begin{array}{*{20}{r}}
  6&4 \\ 
  1&{ - 7} 
\end{array}} \right| + 5\left| {\begin{array}{*{20}{r}}
  6&0 \\ 
  1&5 
\end{array}} \right|$

$ = 2(0 - 20) + 3( - 42 - 4) + 5(30 - 0)$

$ =  - 40 - 138 + 150 =  - 28$

By interchanging rows and columns, we get

$\Delta_{1}=\left|\begin{array}{rrr}2 & 6 & 1 \\ -3 & 0 & 5 \\ 5 & 4 & -7\end{array}\right| \quad$ (Expanding along first column)

$=2\left|\begin{array}{rr}
0 & 5 \\
4 & -7
\end{array}\right|-(-3)\left|\begin{array}{rr}
6 & 1 \\
4 & -7
\end{array}\right|+5\left|\begin{array}{ll}
6 & 1 \\
0 & 5
\end{array}\right|$

${ = 2(0 - 20) + 3( - 42 - 4) + 5(30 - 0)}$

${ =  - 40 - 138 + 150 =  - 28}$

Clearly $\Delta=\Delta_{1}$

Hence, Property $1$ is verified.

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  • [JEE MAIN 2021]

The determinant $\left| {\begin{array}{*{20}{c}}{^x{C_1}}&{^x{C_2}}&{^x{C_3}}\\ {^y{C_1}}&{^y{C_2}}&{^y{C_3}}\\{^z{C_1}}&{^z{C_2}}&{^z{C_3}}\end{array}} \right|$ $=$