Solution:
Given:
[tex]-5-7i[/tex]The conjugate of (-5 -7i) is (-5+7i)
Hence, the product is;
[tex]\begin{gathered} (-5-7i)(-5+7i) \\ Expanding\text{ the bracket,} \\ =25-35i+35i+49 \\ =25+0+49 \\ =74 \end{gathered}[/tex]Therefore, the product is 74.
