Step 1: Determine the conjugate of the denominator. ( to find the conjugate just change the sign of the imaginary part ).
In this example, the conjugate of $ \color{orangered}{ \frac{ 73 }{ 1000 }-\frac{ 1 }{ 100 }i }\, $ is $ \color{blue}{ \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i } $.
Step 2: Multiply both the numerator and denominator by the conjugate:
$$\begin{aligned} \frac{ \frac{ 3189 }{ 1000 }+\frac{ 239 }{ 50 }i }{ \frac{ 73 }{ 1000 }-\frac{ 1 }{ 100 }i } &= \frac{ \frac{ 3189 }{ 1000 }+\frac{ 239 }{ 50 }i }{ \frac{ 73 }{ 1000 }-\frac{ 1 }{ 100 }i } \cdot \frac{ \color{blue}{ \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i } }{ \color{blue}{ \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i } } = \\[1 em] &= \frac{ \left( \frac{ 3189 }{ 1000 }+\frac{ 239 }{ 50 }i \right) \cdot \left( \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i \right) }{ \left( \frac{ 73 }{ 1000 }-\frac{ 1 }{ 100 }i \right) \cdot \left( \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i \right) } \end{aligned} $$Step 3: Simplify numerator and denominator (use $\color{blue}{i^2 = -1}$)
$$ \begin{aligned} \left( \frac{ 3189 }{ 1000 }+\frac{ 239 }{ 50 }i \right) \cdot \left( \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i \right) &= \frac{ 3189 }{ 1000 } \cdot \frac{ 73 }{ 1000 } + \frac{ 3189 }{ 1000 } \cdot \left(\frac{ 1 }{ 100 } \,i \right) + \left( \frac{ 239 }{ 50 } \,i \right) \cdot \left(\frac{ 73 }{ 1000 } \right) + \left( \frac{ 239 }{ 50 } \,i \right) \cdot \left(\frac{ 1 }{ 100 } \,i \right) = \\[1 em] &= \frac{ 232797 }{ 1000000 } + \frac{ 3189 }{ 100000 } \, i + \frac{ 17447 }{ 50000 } \, i + \frac{ 239 }{ 5000 } \color{blue}{(-1)} = \\[1 em] &= \frac{ 184997 }{ 1000000 }+\frac{ 38083 }{ 100000 }i\end{aligned} $$ $$ \begin{aligned} \left( \frac{ 73 }{ 1000 }-\frac{ 1 }{ 100 }i \right) \cdot \left( \frac{ 73 }{ 1000 }+\frac{ 1 }{ 100 }i \right) &= \frac{ 73 }{ 1000 } \cdot \frac{ 73 }{ 1000 } + \frac{ 73 }{ 1000 } \cdot \left(\frac{ 1 }{ 100 } \,i \right) + \left( -\frac{ 1 }{ 100 } \,i \right) \cdot \left(\frac{ 73 }{ 1000 } \right) + \left( -\frac{ 1 }{ 100 } \,i \right) \cdot \left(\frac{ 1 }{ 100 } \,i \right) = \\[1 em] &= \frac{ 5329 }{ 1000000 } + \frac{ 73 }{ 100000 } \, i -\frac{ 73 }{ 100000 } \, i -\frac{ 1 }{ 10000 } \color{blue}{(-1)} = \\[1 em] &= \frac{ 5429 }{ 1000000 }\end{aligned} $$Step 4: Separate real and imaginary parts:
$$ \frac{ \frac{ 3189 }{ 1000 }+\frac{ 239 }{ 50 }i }{ \frac{ 73 }{ 1000 }-\frac{ 1 }{ 100 }i } = \frac{ \frac{ 184997 }{ 1000000 }+\frac{ 38083 }{ 100000 }i }{ \frac{ 5429 }{ 1000000 } } = \frac{ \frac{ 184997 }{ 1000000 } }{ \frac{ 5429 }{ 1000000 } } + \frac{ \frac{ 38083 }{ 100000 } }{ \frac{ 5429 }{ 1000000 } } i= \frac{ 184997 }{ 5429 }+\frac{ 380830 }{ 5429 }i $$