Add 42/81 and 75/20
1st number: 42/81, 2nd number: 3 15/20
42/81 + 75/20 is 461/108.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 20 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 81 × 20 = 1620,
42/81 = 42 × 20/81 × 20 = 840/1620 - Likewise, for the 2nd fraction, since 20 × 81 = 1620,
75/20 = 75 × 81/20 × 81 = 6075/1620 - Add the two like fractions:
840/1620 + 6075/1620 = 840 + 6075/1620 = 6915/1620 - 6915/1620 simplified gives 461/108
- So, 42/81 + 75/20 = 461/108
In mixed form: 429/108
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/81+75/20 42/81+75/40 42/81+75/60