Add 21/84 and 20/15
1st number: 21/84, 2nd number: 1 5/15
21/84 + 20/15 is 19/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 15 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
21/84 = 21 × 5/84 × 5 = 105/420 - Likewise, for the 2nd fraction, since 15 × 28 = 420,
20/15 = 20 × 28/15 × 28 = 560/420 - Add the two like fractions:
105/420 + 560/420 = 105 + 560/420 = 665/420 - 665/420 simplified gives 19/12
- So, 21/84 + 20/15 = 19/12
In mixed form: 17/12
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