Add 10/21 and 9/20
10/21 + 9/20 is 389/420.
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,
10/21 = 10 × 20/21 × 20 = 200/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
9/20 = 9 × 21/20 × 21 = 189/420 - Add the two like fractions:
200/420 + 189/420 = 200 + 189/420 = 389/420 - So, 10/21 + 9/20 = 389/420
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