Add 20/42 and 63/81
20/42 + 63/81 is 79/63.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 81 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 42 × 27 = 1134,
20/42 = 20 × 27/42 × 27 = 540/1134 - Likewise, for the 2nd fraction, since 81 × 14 = 1134,
63/81 = 63 × 14/81 × 14 = 882/1134 - Add the two like fractions:
540/1134 + 882/1134 = 540 + 882/1134 = 1422/1134 - 1422/1134 simplified gives 79/63
- So, 20/42 + 63/81 = 79/63
In mixed form: 116/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42+63/81 20/84+63/81 60/42+63/81