Answer
$1+2\sqrt2, 9+4\sqrt2$
Work Step by Step
z = $1+\sqrt 8$
The complex conjugate of a+bi is a-bi. There is no imaginary term, so its complex conjugate is the same number.
Multiplying the complex number by its conjugate gives : ($1+\sqrt 8$) * ($1+\sqrt 8$) = $1+2\sqrt 8+8 = 9+2\sqrt 8 = 9+4\sqrt2$