Answer
See image:
.
Work Step by Step
Rewrite as
$\displaystyle \frac{z-8}{-1}=\frac{x^{2}}{1^{2}}+\frac{y^{2}}{1^{2}}$
Compare with Table 11.1 and conclude that this is an elliptical paraboloid which opens down, with the vertex raised up 8 units.
The traces in xz and yz planes are parabolas.
The traces in planes parallel to the xy plane are circles (special case of ellipses).
