Add 72/20 and 20/21
1st number: 3 12/20, 2nd number: 20/21
72/20 + 20/21 is 478/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
20/21 = 20 × 20/21 × 20 = 400/420 - Add the two like fractions:
1512/420 + 400/420 = 1512 + 400/420 = 1912/420 - 1912/420 simplified gives 478/105
- So, 72/20 + 20/21 = 478/105
In mixed form: 458/105
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