
ISMAIL A. answered 05/09/21
PhD in Computer Science. 20+ years of Experience.
It is actually relatively simple if you read it as "Sum of the element values should be the same". Therefore,
i) [Empty] = {{0}, {-1,1}}
ii) [-1] = {{-1,0}}
iv) {{0}, {-1,1}}
This should give an idea. Good luck!