Add 9/18 and 5/21
9/18 + 5/21 is 31/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
9/18 = 9 × 7/18 × 7 = 63/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
5/21 = 5 × 6/21 × 6 = 30/126 - Add the two like fractions:
63/126 + 30/126 = 63 + 30/126 = 93/126 - 93/126 simplified gives 31/42
- So, 9/18 + 5/21 = 31/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 9/18+10/21 9/36+5/21 9/18+5/42 27/18+5/21 9/18+15/21 9/54+5/21 9/18+5/63 45/18+5/21 9/18+25/21 9/90+5/21 63/18+5/21 9/18+35/21