Add 18/20 and 12/21
18/20 + 12/21 is 103/70.
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,
18/20 = 18 × 21/20 × 21 = 378/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
12/21 = 12 × 20/21 × 20 = 240/420 - Add the two like fractions:
378/420 + 240/420 = 378 + 240/420 = 618/420 - 618/420 simplified gives 103/70
- So, 18/20 + 12/21 = 103/70
In mixed form: 133/70
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