Add: (4d-3)+12d+4).

The given expression is: (4d-3)+12d+4.

To simplify this expression, we will first remove the parentheses by combining similar terms:

4d + (-3) + 12d + 4.

Next, we can combine the like terms:

(4d + 12d) + (-3 + 4) = 16d + 1.

Therefore, the simplified expression is 16d + 1.