The solution for x and z looks somewhat like my solution – but I don’t know if this is by accident. Because I don’t know how to read this numbers. Clarification would be great. Thanks

One thing, I have runned this code and obtained 1.50000000e+01 and not 1.50000000e+03, and the same pattern in the other values. -16 and +00.

In python notation, that e that appears is related to scientific notation. So whenever you see it, it is just 10^something

So, the last value, 5.00000000e+02 is just 5.00000000\cdot10^{2}, which is just 500 in that case.

The value related to y, if you see it, it is 10^{-16} which is a value very close to zero. It sometimes happens because on the way Python handles floating numbers. You can always round the solution to make it look better.