a) A U B = {1,2,3,4,5,6,7,8,9}
b) A U C = {1,2,3,4,5,6,7,12}
c) B U C = {1,2,3,5,6,7,8,9,12}
d) A N B = {5,6,7}
e) A N C = {1,2,37}
f) B N C = {7}
g) A U B U C = {1,2,3,4,5,6,7,8,9,12}
h) A N B N C = {7}
i) A / B = {1,2,3,4}
j) B / C = {5,6,8,9}
k)A / C = {4,5,6}
l) A U (B N C) = A U 7 = {1,2,3,4,5,6,7}