If #(a,b,c,d)means you subtract the sum of the terms from zero, and # (4,-8,11,d)=14, then d=

answer and explain

#(a,b,c,d) = 0-(a+b+c+d)

0-(4+(-8)+11+d) = 14
-(d+7) = 14
d+7 = -14
d = -21