Subtract 4/21 from 20/15, Solve 1 5/15

Subtract 4/21 from 20/15

1^st number: 1 5/15, 2^nd number: 4/21

20/15 - 4/21 is 8/7.

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,
4/21 = 4 × 5/21 × 5 = 20/105
Subtract the two like fractions:
140/105 - 20/105 = 140 - 20/105 = 120/105
After reducing the fraction, the answer is 8/7
In mixed form: 11/7

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