Add 15/21 and 9/20
15/21 + 9/20 is 163/140.
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,
15/21 = 15 × 20/21 × 20 = 300/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
9/20 = 9 × 21/20 × 21 = 189/420 - Add the two like fractions:
300/420 + 189/420 = 300 + 189/420 = 489/420 - 489/420 simplified gives 163/140
- So, 15/21 + 9/20 = 163/140
In mixed form: 123/140
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