To solve this expression, we need to simplify each fraction separately and then perform the addition.

Starting with the first fraction: -3/-4, we can simplify it by multiplying both the numerator and denominator by -1 to get 3/4.

Next, let's simplify the second fraction: 11/-15. There are no common factors between 11 and -15, so we cannot simplify it further.

Now, let's simplify the third fraction: -1/2. It is already in its simplest form.

Now, we can add the fractions together:

3/4 + 11/-15 + -1/2

To add fractions, we need to find a common denominator. The common denominator for 4, -15, and 2 is 60.

Converting the fractions to have a denominator of 60:

(3/4) * (15/15) = 45/60
(11/-15) * (4/4) = -44/60
(-1/2) * (30/30) = -30/60

Now, we can add the fractions:

45/60 + -44/60 + -30/60

To add fractions, we add the numerators and keep the common denominator:

(45 + -44 + -30)/60

Simplifying the numerator:

(-29)/60

Therefore, the final answer is -29/60.