Answer:
Uc = {x | x is in I and x<-3 and x>6}
Step-by-step explanation:
The complement of a set is another set with all the elements out of the original set. Then, we have the set
U = {x | x is in I and -3≤x≤6}
so, the complement will be all the x values in I to the left of -3 and to the right of 6, without includind the -3 and 6. In set terms it is
Uc = {x | x is in I and x<-3 and x>6} or
Uc = {x | x is in I and x is in (-∞,-3) U (6,∞)}