Add 21/90 and 20/81
21/90 + 20/81 is 389/810.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 81 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 90 × 9 = 810,
21/90 = 21 × 9/90 × 9 = 189/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
20/81 = 20 × 10/81 × 10 = 200/810 - Add the two like fractions:
189/810 + 200/810 = 189 + 200/810 = 389/810 - So, 21/90 + 20/81 = 389/810
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