OK, let's do this. We've got 71731 and 35175, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 5 and the borrow 0 from 1 in column 1 and get -4.
We add -4 to 10 and get 6 as the first digit of the result.

Step 2: We'll start by subtracting the digit 7 and the borrow 1 from 3 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 1 and the borrow 1 from 7 in column 3 and get 5.
5 is the next digit of our result.

Step 4: We'll start by subtracting the digit 5 and the borrow 0 from 1 in column 4 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

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

So, 71731 - 35175 = 36556.