Add 20/15 and 81/21
1st number: 1 5/15, 2nd number: 3 18/21
20/15 + 81/21 is 109/21.
Steps for adding fractions
- 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,
81/21 = 81 × 5/21 × 5 = 405/105 - Add the two like fractions:
140/105 + 405/105 = 140 + 405/105 = 545/105 - 545/105 simplified gives 109/21
- So, 20/15 + 81/21 = 109/21
In mixed form: 54/21
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