Some interesting fill in puzzle
Fill in the circles with any number(no repeating) in a way that the sum of the numbers on a row or column are the same.
@boldsidewinder-0 This is a fun problem!
I let a=leftmost ?, b=topmost ?, and c=bottomost ?
Then, $$17+b=9+b+c\Longrightarrow c=8,$$ so
$$13+c=17+b\Longrightarrow b=13+8-17=4$$ and $$8+a=13+c\Longrightarrow a=13+8-8=13.$$
That gives $$(a,b,c)=(13,4,8),$$ and those numbers work! (with the sum being 21).