By using properties of determinant, show that \(\left| {\begin{array}{*{20}{c}} {x + y + 2z}&x&y \\ z&{y + z + 2x}&y \\ z&x&{z + x + 2y} \end{array}} \right| = 2{\left( {x + y + z} \right)^3}\)
Using cofactors of elements of third column, evaluate \(\Delta = \left| {\begin{array}{*{20}{c}} 1&x&{yz} \\ 1&y&{zx} \\ 1&z&{xy} \end{array}} \right|\)