5. Find Subtraction of 3846 and 1756 using 9's complement

Solution:

9's complement subtraction steps :

1. At first, find 9's complement of the B(subtrahend).
2. Then add it to the A(minuend).
3. If the final carry over of the sum is 1, then it is dropped and 1 is added to the result.
4. If there is no carry over, then 9's complement of the sum is the final result and it is negative.

Here A = 3846, B = 1756.
Find A - B = ? using 9's complement
First find 9's complement of B = 1756


Step-1: 9's complement of 1756 is obtained by subtracting each digit from 9999

	9	9	9	9
-	1	7	5	6
	8	2	4	3

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Step-2: Now Add this 8243 to 3846

	1
	3	8	4	6
+	8	2	4	3
1	2	0	8	9

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Step by step solution of 3846 + 8243 = 12089

Write the numbers, so that each digit lines up vertically

	3	8	4	6
+	8	2	4	3

Step-1 :
`=6+3`
`=9`
Write the 9 in the sum place

	3	8	4	6
+	8	2	4	3
				9

Step-2 :
`=4+4`
`=8`
Write the 8 in the sum place

	3	8	4	6
+	8	2	4	3
			8	9

Step-3 :
`=8+2`
`=10`
Write the 0 in the sum place and carry the 1 to the next carry place

	1
	3	8	4	6
+	8	2	4	3
		0	8	9

Step-4 :
`=1+3+8`
`=12`
Write the 12 in the sum place

	1
	3	8	4	6
+	8	2	4	3
1	2	0	8	9

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The left most bit (1) of the result (12089) is called carry and add it to the rest part of the result (2089)

			1
	2	0	8	9
+				1
	2	0	9	0

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So answer is 2090

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