Question 202480
I'll do the first three to get you started.





Remember, the big "U" (set union) between the two sets tells us to combine the two sets to form a new (possibly larger) set. For example, let's say we have 

the two sets 


X = {1, 2, 5} and Y = {1, 3, 4, 5}


The union of these two sets is simply the combination of the two sets (remember to remove duplicates)



X U Y = {1, 2, 3, 4, 5}



The upside down U is the set intersection. This just forms a new set with any elements that the two sets have in common. So using the same sets, we get


*[Tex \LARGE X \cap Y = \left\{1, 5\right\}]



Take note how 1 and 5 are in both sets




Also, the tick mark right after the set tells you to form a new set with every element in U that is NOT in A. In other words, form the set that has every 

letter but the ones found in the given set


So in this case, 


*[Tex \LARGE A' = \left\{a, b, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z\right\}]


and 



*[Tex \LARGE B' = \left\{a, b, c, d, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z\right\}]


-------------

a)


Simply combine the two sets (and remove duplicates) to get:



*[Tex \LARGE A \cup B = \left\{c, d, e, f, g, h, k \right\}]



-------------

b)


Since sets A and B only have the elements "e" and "f" in common, this means that:



*[Tex \LARGE A \cap B = \left\{e, f\right\}]



-------------

c)


Now since the two sets A' and B' (see above) have the elements a, b, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, and z in common, this means that 



*[Tex \LARGE A' \cap B' = \left\{a, b, c, d, g, h i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z\right\}]