#### Answer

4568

#### Work Step by Step

First, the 3 in the ones place is less than 5, so in order to subtract we first have to regroup from the tens digit to turn 3 to 13. Then we subtract 13-5 = 8 for the ones column.
Next, since the 6 in the tens place became 5, we have to regroup again from the hundreds digit to turn 5 to 15. We subtract 15-9 = 6 for the tens column.
Next, we subtract 7-2 = 5 for the hundreds column.
Finally, we subtract 5-1 = 4 for the thousands column..
From the 4 in the thousands place, 5 in the hundreds place, 6 in the tens place, and 8 in the ones place, we get 4568.