Add 3/4 and 20/21
3/4 + 20/21 is 143/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 4 × 21 = 84,
3/4 = 3 × 21/4 × 21 = 63/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
20/21 = 20 × 4/21 × 4 = 80/84 - Add the two like fractions:
63/84 + 80/84 = 63 + 80/84 = 143/84 - So, 3/4 + 20/21 = 143/84
In mixed form: 159/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/4+20/21 3/4+40/21 3/8+20/21 3/4+20/42 9/4+20/21 3/4+60/21 3/12+20/21 3/4+20/63 15/4+20/21 3/20+20/21 21/4+20/21 3/28+20/21