Add 72/21 and 81/30
1st number: 3 9/21, 2nd number: 2 21/30
72/21 + 81/30 is 429/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
72/21 = 72 × 10/21 × 10 = 720/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
81/30 = 81 × 7/30 × 7 = 567/210 - Add the two like fractions:
720/210 + 567/210 = 720 + 567/210 = 1287/210 - 1287/210 simplified gives 429/70
- So, 72/21 + 81/30 = 429/70
In mixed form: 69/70
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