The inverse of $ z $ is:
$$ z^{-1} = -\frac{ 5 }{ 169 }+\frac{ 12 }{ 169 }i $$We will denote the inverse of $ z $ as $ z_1 $. The inverse can be found in three steps.
Step 1: Rewrite complex number as its reciprocal
$$ z_1 = \frac{1}{ -5-12i } $$Step 2: Multiply top and bottom by complex conjugate of $ z $
$$ z_1 = \frac{1}{ -5-12i } \cdot \frac{ -5+12i }{ -5+12i } $$Step 3: Simplify
$$ z_1 = \frac{ -5+12i }{ 169 } $$$$ z_1 = \frac{ -5 }{ 169 } + \frac{ 12 }{ 169 } \cdot i$$$$ z_1 = -\frac{ 5 }{ 169 }+\frac{ 12 }{ 169 }i $$