To simplify the given expression, we need to first convert the mixed numbers to improper fractions.

So, 3 11/21 = (321 + 11)/21 = 64/21
and 2 4/45 = (245 + 4)/45 = 94/45

Now, the expression becomes:

14 - 13/2 (64/21 - 94/45)
= 14 - 13/2 (64/21 - 94/45)
= 14 - 13/2 ((6445 - 9421)/(2145))
= 14 - 13/2 ((2880 - 1974)/(945))
= 14 - 13/2 (906/945)
= 14 - 13/2 (302/315)
= 14 - (13302)/(2*315)
= 14 - 395/35
= 14 - 11 2/7
= 2 5/7

Therefore, 14 - 13/2 * (3 11/21 - 2 4/45) simplifies to 2 5/7.