Add (−34) and (12).

To add (−34) and (12), simply add the numbers together:

(-34) + (12) = -22.

Therefore, the sum of (-34) and (12) is -22.

To add (-34) and (12), follow these steps:

1. Place the numbers vertically, one above the other, with the negative sign in front of -34.

-34
+ 12

2. Start by adding the numbers in the ones place value column. Here, we have 4 + 2, which equals 6. Write down the sum under the line.

-34
+ 12
____
6

3. Now, move to the tens place value column. Since we only have -34 in the tens place, we can consider it as -30. Therefore, -30 + 10 equals -20. Write this sum under the line.

-34
+ 12
____
-20

4. Finally, write the full sum below the line. The result of adding (-34) and (12) is -20.

-34
+ 12
____
-20

So, (-34) + (12) equals -20.