Let's get this math done. We have 68792 and 155, and we're going to subtract the second number from the first.

Step 1: We'll start by subtracting the digit 5 and the borrow 0 from 2 in column 1 and get -3.
We add -3 to 10 and get 7 as the first digit of the result.

Step 2: We'll start by subtracting the digit 5 and the borrow 1 from 9 in column 2 and get 3.
3 is the next digit of our result.

Step 3: We'll start by subtracting the digit 1 and the borrow 0 from 7 in column 3 and get 6.
6 is the next digit of our result.

Step 4: We'll start by subtracting the digit 0 and the borrow 0 from 8 in column 4 and get 8.
8 is the next digit of our result.

Step 5: We'll start by subtracting the digit 0 and the borrow 0 from 6 in column 5 and get 6.
6 is the next digit of our result.

So, 68792 - 155 = 68637.