Add 81/21 and 7/20
1st number: 3 18/21, 2nd number: 7/20
81/21 + 7/20 is 589/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
81/21 = 81 × 20/21 × 20 = 1620/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
7/20 = 7 × 21/20 × 21 = 147/420 - Add the two like fractions:
1620/420 + 147/420 = 1620 + 147/420 = 1767/420 - 1767/420 simplified gives 589/140
- So, 81/21 + 7/20 = 589/140
In mixed form: 429/140
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