Answer
109
Work Step by Step
First column: 2 - 3 is turned into 12 - 3 as 2 < 3
12 - 3 = 9
The 9 is written in the first column and the extra 1 digit added in the tens position to the 2 is carried to the next column.
Second column: 8 - 7 - additional carried 1 from the previous column = 0
The 0 is written in the second column.
Third column: 8 - 7 = 1
The 1 is written in the last column.
The digits we are left with are 1, 0 and 9 , so therefore the solution to the question is 109.
