The principle is the same as in addition. Reduce the fractions, if they
have different denominators, to a common denominator, and then take the
difference of the numerators. In the case of mixed numbers, subtract the
whole numbers and the fractions separately.
EXAMPLE 1: Take 4-5/21 from 6-3/7.
3 5 3 5
6- - 4-- = 6 - 4 + - - --
7 21 7 21
9 - 5
= 2 + -----
21
4 4
= 2 + -- = 2-- _Ans._
21 21
If the fractional part of the number to be subtracted be greater than
the fractional part of the other number, we proceed as follows:
EXAMPLE 2: From 7-4/15 take 4-11/25.
4 11 4 11
7-- - 4-- = 7 - 4 + -- - --
15 25 15 25
20 - 33
= 3 + -------
75
75 + 20 - 33
= 2 + ------------
75
62 62
= 2 + -- = 2-- _Ans._
75 75
EXAMPLE 3: Simplify 3-2/9 + 4-5/7 - 5-13/21 + 2/35 - 1-14/15. Given
expression:
2 5 13 2 14
= 3 + 4 - 5 - 1 + - + - - -- + -- - --
9 7 21 35 15
70 + 225 - 195 + 18 - 294
= 1 + -------------------------
315
313 - 489[15]
= 1 + ---------
315
628 - 489 139
= --------- = --- _Ans._
315 315
[15] Obtained by adding all the numerators with + before them, and
then all those with - before them.