Finding the Solution for C - (A-B) in Discrete Mathematics

[nicnicman]

Here's the problem:
Suppose U = {x | -10 ≤ x ≤ 10 and x ∈ Z}, A = all multiples of 2, B = all multiples of 3, and C = {-10, -9, -8, -6, -4, 0, 1, 3, 5, 6, 8, 10}.

Find C - (A-B).

Solution:
A = {-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10}
B = {-9, -6, -3, 0, 3, 6, 9}
C = {-10, -9, -8, -6, -4, 0, 1, 3, 5, 6, 8, 10}

C - (A-B) = C - {-10, -8, -4, -2, 2, 4, 8, 10}
= {-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10} - {-10, -8, -4, -2, 2, 4, 8, 10}
= {-9, -6, 0, 1, 3, 5, 6}

Does this look right? Thanks for any suggestions!

 

[SammyS]

Here's the problem:
Suppose U = {x | -10 ≤ x ≤ 10 and x ∈ Z}, A = all multiples of 2, B = all multiples of 3, and C = {-10, -9, -8, -6, -4, 0, 1, 3, 5, 6, 8, 10}.

Find C - (A-B).

Solution:
A = {-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10}
B = {-9, -6, -3, 0, 3, 6, 9}
C = {-10, -9, -8, -6, -4, 0, 1, 3, 5, 6, 8, 10}

C - (A-B) = C - {-10, -8, -4, -2, 2, 4, 8, 10}
= {-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10} - {-10, -8, -4, -2, 2, 4, 8, 10}
= {-9, -6, 0, 1, 3, 5, 6}

Does this look right? Thanks for any suggestions!

Looks right to me.

 

[nicnicman]

Okay, thanks for the help!