Add 18/21 and 18/20
18/21 + 18/20 is 123/70.
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,
18/21 = 18 × 20/21 × 20 = 360/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
18/20 = 18 × 21/20 × 21 = 378/420 - Add the two like fractions:
360/420 + 378/420 = 360 + 378/420 = 738/420 - 738/420 simplified gives 123/70
- So, 18/21 + 18/20 = 123/70
In mixed form: 153/70
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