with(plots); -1 

with(VectorCalculus); -1 

`:=`(P1, 
implicitplot3d(`+`(`*`(2, `*`(y)), `*`(4, `*`(z)), `-`(5)) = 0, x = -2 
.. 2, y = -2 .. 2, z = 0 .. 2, style = surface, color = blue, axes = 
boxed)) 

PLOT3D(ISOSURFACE(Array(1..10, 1..10, 1..10, 1..4, {(1, 1, 1, 1) = 
-2.0, (1, 1, 1, 2) = -2.0, (1, 1, 1, 3) = -2.0, (1, 1, 1, 4) = -2.0, (1,
 1, 2, 1) = -2.0, (1, 1, 2, 2) = -2.0, (1, 1, 2, 3) = -2.0, (... (1)
 

`:=`(P2, 
implicitplot3d(`+`(`*`(4, `*`(`^`(x, 2))), `*`(4, `*`(`^`(y, 2))), 
`-`(`*`(`^`(z, 2)))) = 0, x = -2 .. 2, y = -2 .. 2, z = 0 .. 2, style = 
surfacecontour, grid = [30, 30, 20])) 

`[Length of
 output exceeds limit of 1000000]` (2)
 

display(P1, P2) 

Plot