Add 20/21 and 21/27
20/21 + 21/27 is 109/63.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 27 is 189
Next, find the equivalent fraction of both fractional numbers with denominator 189 - For the 1st fraction, since 21 × 9 = 189,
20/21 = 20 × 9/21 × 9 = 180/189 - Likewise, for the 2nd fraction, since 27 × 7 = 189,
21/27 = 21 × 7/27 × 7 = 147/189 - Add the two like fractions:
180/189 + 147/189 = 180 + 147/189 = 327/189 - 327/189 simplified gives 109/63
- So, 20/21 + 21/27 = 109/63
In mixed form: 146/63
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