[tex] \frac{10}{ - 8 - 6i} \times \frac{ - 8 + 6i}{ - 8 + 6i} = \frac{ - 80 - 60i}{( - 8 + 6i)( - 8 - 6i)} \\ = \frac{ - 80 - 60i}{ - 64 - 36 {i}^{2} } = \frac{ - 80 - 60i}{ - 64 + 36} \\ = \frac{ - 20 - 15i}{ - 16 + 9} = \frac{ - 20 - 15i}{ - 7} [/tex]
