Subtract 21/84 from 20/15, Solve 1 5/15

Subtract 21/84 from 20/15

1^st number: 1 5/15, 2^nd number: 21/84

20/15 - 21/84 is 13/12.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 84 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 15 × 28 = 420,
20/15 = 20 × 28/15 × 28 = 560/420
Likewise, for the 2nd fraction, since 84 × 5 = 420,
21/84 = 21 × 5/84 × 5 = 105/420
Subtract the two like fractions:
560/420 - 105/420 = 560 - 105/420 = 455/420
After reducing the fraction, the answer is 13/12
In mixed form: 11/12

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