To perform additions using 1's complementation, we first need to convert the hexadecimal numbers to their binary representations. Let's work through the given additions step by step:

1. Convert hexadecimal numbers to binary:
- FA8C = 1111101010001100
- 7A9B = 0111101010011011
- 2578 = 0010010101111000
- 807F = 1000000001111111

2. Perform the addition:
- FA8C + 7A9B = 1111101010001100 + 0111101010011011

To add two binary numbers, we start from the rightmost bit and proceed towards the left, performing addition as follows:

1111101010001100 (FA8C)
+ 0111101010011011 (7A9B)
---------------------
1 0111010100100111

The result of the addition in binary form is 10111010100100111.

3. Convert the binary sum back to hexadecimal:
10111010100100111 = B527

Therefore, the addition of FA8C and 7A9B in hexadecimal using 1's complementation is B527.

Similarly, we can perform the remaining additions:

- 7A9B + 2578 = 0111101010011011 + 0010010101111000

0111101010011011 (7A9B)
+ 0010010101111000 (2578)
---------------------
1 1001110000010011

The result of the addition in binary form is 11001110000010011.

Converting the binary sum back to hexadecimal:
11001110000010011 = CE13

Therefore, the addition of 7A9B and 2578 in hexadecimal using 1's complementation is CE13.

- 2578 + 807F = 0010010101111000 + 1000000001111111

0010010101111000 (2578)
+ 1000000001111111 (807F)
---------------------
10100101101101111

The result of the addition in binary form is 10100101101101111.

Converting the binary sum back to hexadecimal:
10100101101101111 = A6D7

Therefore, the addition of 2578 and 807F in hexadecimal using 1's complementation is A6D7.

In conclusion, the additions using 1's complementation are:
- FA8C + 7A9B = B527
- 7A9B + 2578 = CE13
- 2578 + 807F = A6D7

Any body know means send it frends