\[1)\ (1 - 6i) + z = - 4 - 7i\]
\[1 - 6i + z = - 4 - 7i\]
\[z = - 5 - i.\]
\[2)\ \left( 2\sqrt{5} - 3\sqrt{3}i \right) - z = \sqrt{5} + \sqrt{3}i\]
\[2\sqrt{5} - 3\sqrt{3}i = z + \sqrt{5} + \sqrt{3}i\]
\[z = \sqrt{5} - 4\sqrt{3}i.\]
\[3)\ (5 - 4i) - z = 3 - 5i\]
\[5 - 4i = z + 3 - 5i\]
\[z = 2 + i.\]
\[4)\ z + \left( 5 - \sqrt{2} \right)i = 6 - i\]
\[z + 5i - \sqrt{2}i = 6 - i\]
\[z = 6 - 6i + \sqrt{2}i\]
\[z = 6 + \left( \sqrt{2} - 6 \right)i.\]