To solve this expression, we need to follow the order of operations (PEMDAS).

First, we calculate inside the parentheses:
123115 divided by 5 = 24623
22757 divided by 7 = 3251

Now, we subtract these two results:
24623 - 3251 = 21372

Next, we multiply this result by 6:
6 * 21372 = 128232

Now, we divide this by 8:
128232 / 8 = 16029

Finally, we add 7981 to this result:
16029 + 7981 = 24010

Therefore, the solution is 24010.