1.) hyperbolic paraboloid

2.) Rewrite as $-4x^2-9y^2+z^2 = 36$ then divide by $36$ to get $$-\frac{4}{36} x^2 - \frac{9}{36} y^2 + \frac{1}{36}z^2 = 1,$$ which is equivalent to $$-\frac{x^2}{3^2} - \frac{y^2}{2^2} + \frac{z^2}{6^2} = 1,$$ the formula for a hyperboloid of $2$ sheets.

3.) cone

4.) hyperbolic paraboloid

5.) hyperboloid in $1$-sheet

6.) elliptic paraboloid

7.) ellipsoid