Let's dive into this subtraction. We'll start with 784214 and subtract 70174 from it.

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

Step 2: We'll start by subtracting the digit 7 and the borrow 0 from 1 in column 2 and get -6.
We add -6 to 10 and get 4 as the next digit of the result.

Step 3: We'll start by subtracting the digit 1 and the borrow 1 from 2 in column 3 and get 0.
0 is the next digit of our result.

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

Step 5: We'll start by subtracting the digit 7 and the borrow 0 from 8 in column 5 and get 1.
1 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, 784214 - 70174 = 714040.