Which expression represents half of the two numbers (n + 1) and (n + 2)?
To find one-half of the sum, let's add them together and then divide by 2:
(n + 1) + (n + 2) = n + 1 + n + 2
Dividing by 2, (n + 1 + n + 2) / 2
+449 
+ n + 1 + 2
