NO....
Yes. If equals are added to equals, then the results of the additions are equal.
When equals are added to equals, you don't necessarily get wholes. But whatever you do get, they're equal.
Yes they are.
50
23
Equals to? When added to what?
Any number added to its negative equals zero.
The numbers are 6 and -20
-2 and -4 do that.
-53
negative
140