Add 81/84 and 9/20
81/84 + 9/20 is 99/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
81/84 = 81 × 5/84 × 5 = 405/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
9/20 = 9 × 21/20 × 21 = 189/420 - Add the two like fractions:
405/420 + 189/420 = 405 + 189/420 = 594/420 - 594/420 simplified gives 99/70
- So, 81/84 + 9/20 = 99/70
In mixed form: 129/70
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