Let's get this math done. We have 799756 and 5598, and we're going to subtract the second number from the first.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 6 in column 1 and get -2.
We add -2 to 10 and get 8 as the first digit of the result.

Step 2: We'll start by subtracting the digit 9 and the borrow 1 from 5 in column 2 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

Step 3: We'll start by subtracting the digit 5 and the borrow 1 from 7 in column 3 and get 1.
1 is the next digit of our result.

Step 4: We'll start by subtracting the digit 5 and the borrow 0 from 9 in column 4 and get 4.
4 is the next digit of our result.

Step 5: We'll start by subtracting the digit 0 and the borrow 0 from 9 in column 5 and get 9.
9 is the next digit of our result.

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

So, 799756 - 5598 = 794158.