1. The problem statement, all variables and given/known data
Use Mathematica to calculate the Gaussian curvature of the plane Ax+By+Cz=D, in which A, B, C, and D are constants and C≠0.

Use the following data:

2. Relevant equations

3. The attempt at a solution
First I found the line curvature. As here:

That code gets the result = 0.
So, I know that the curvature needs to be 0, even with the Gaussian curvature.

I have looked at Gaussian curve code in Mathematica but I cant quite figure out how to get it to work.
I was told that I need to translate it to a 'u' and 'v' parameterized surface, but I have no idea how to do that...especially in Mathematica.
Here is my Gaussian Curvature attempt:

I just cant seem to get it to be 0. What am I doing wrong?

Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?