Let's dive into this subtraction. We'll start with 42489 and subtract 38780 from it.

Step 1: We'll start by subtracting the digit 0 and the borrow 0 from 9 in column 1 and get 9.
9 is the first digit of our result.

Step 2: We'll start by subtracting the digit 8 and the borrow 0 from 8 in column 2 and get 0.
0 is the next digit of our result.

Step 3: We'll start by subtracting the digit 7 and the borrow 0 from 4 in column 3 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 4: We'll start by subtracting the digit 8 and the borrow 1 from 2 in column 4 and get -7.
We add -7 to 10 and get 3 as the next digit of the result.

Step 5: We'll start by subtracting the digit 3 and the borrow 1 from 4 in column 5 and get 0.
0 is the next digit of our result.

So, 42489 - 38780 = 3709.