Please write step by step, and solve all question. I will mark you as brainliest answer!​

11, 10

Step-by-step explanation:

n(B') = 2+5+12 = 19 ; the numbers that are not included in B

n(B∩C) = y-1 +9  = y+8 ; what belongs to both B and C

a)

n(B') = n(B∩C)

19 = y +8 ; subtract 8 from both sides

19-8 = y-8+8

11 = y

b)

n(A∪B∪C) =y -1 = 11 -1 = 10 ; is what belongs to A and B and C in the same time

your answer is b ^w^ hope i