Add 20/21 and 4/15
20/21 + 4/15 is 128/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
20/21 = 20 × 5/21 × 5 = 100/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
4/15 = 4 × 7/15 × 7 = 28/105 - Add the two like fractions:
100/105 + 28/105 = 100 + 28/105 = 128/105 - So, 20/21 + 4/15 = 128/105
In mixed form: 123/105
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