Subtract 27/21 from 20/15, Solve 1 5/15

Subtract 27/21 from 20/15

1^st number: 1 5/15, 2^nd number: 1 6/21

20/15 - 27/21 is 1/21.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 15 × 7 = 105,
20/15 = 20 × 7/15 × 7 = 140/105
Likewise, for the 2nd fraction, since 21 × 5 = 105,
27/21 = 27 × 5/21 × 5 = 135/105
Subtract the two like fractions:
140/105 - 135/105 = 140 - 135/105 = 5/105
After reducing the fraction, the answer is 1/21

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