I just tried the trial and error, sorry I can't give you the exact solution for this question but, I gonna show you how did I get the answer.
(-309)+n+273+65= -63
-273+ (-65) = 338
-338 + (-63) = -401
-401+309 = -92
n= -92
-17+4+n+38=14
-38+(-4) = -42
-42-(-17) = -25
-25-(14)= -11
n = -11
Hope this helps! :)
