10–{12–[(−9)+(−1)]}=?

Answer 1

10 - (12 - (-9 - 1)), think you got the rest from here?

Answer 2

It is not 8

Answer 3

Remember to do the parenthesis first, this is order of operations.

Answer 4

so? It's not 50 either.
Next step:
10 - (12 - (-9 - 1)) = 10 - (12-(-10)) = 10-(12+10) ...