To simplify the expression 4a/2b - 3ab/2 - a/2b + 2ab/2, we first need to find a common denominator for all terms. The common denominator for 2b is 2b.

Now, we rewrite each term with the common denominator:

(4a/2b) - (3ab/2) - (a/2b) + (2ab/2)
= (4a)/(2b) - (3ab)/(2) - (a)/(2b) + (2ab)/(2)

Next, we simplify each term:

(4a)/(2b) = 2a/b
(3ab)/(2) = 3ab/2
(a)/(2b) = a/2b
(2ab)/(2) = ab

Now, substitute the simplified terms back into the expression:

2a/b - 3ab/2 - a/2b + ab

Therefore, the simplified expression is:

2a/b - 3ab/2 - a/2b + ab