No problem, let's work through this together. We're starting with 49121 and are subtracting 47864 from it.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 1 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 6 and the borrow 1 from 2 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 8 and the borrow 1 from 1 in column 3 and get -8.
We add -8 to 10 and get 2 as the next digit of the result.

Step 4: We'll start by subtracting the digit 7 and the borrow 1 from 9 in column 4 and get 1.
1 is the next digit of our result.

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

So, 49121 - 47864 = 1257.