Add 12/21 and 9/20
12/21 + 9/20 is 143/140.
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,
12/21 = 12 × 20/21 × 20 = 240/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
9/20 = 9 × 21/20 × 21 = 189/420 - Add the two like fractions:
240/420 + 189/420 = 240 + 189/420 = 429/420 - 429/420 simplified gives 143/140
- So, 12/21 + 9/20 = 143/140
In mixed form: 13/140
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