Answer
See below.
Work Step by Step
For a complex number $a+bi$, its absolute value is $\sqrt{a^2+b^2}$, its complex conjugate is $a-bi$ and its opposite is: $-a-bi$.
Hence here the absolute value: $\sqrt{8^2}=8$, the complex conjugate: $-8i$, the opposite: $-8i$.
