Add 21/30 and 28/72
21/30 + 28/72 is 49/45.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 72 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 30 × 12 = 360,
21/30 = 21 × 12/30 × 12 = 252/360 - Likewise, for the 2nd fraction, since 72 × 5 = 360,
28/72 = 28 × 5/72 × 5 = 140/360 - Add the two like fractions:
252/360 + 140/360 = 252 + 140/360 = 392/360 - 392/360 simplified gives 49/45
- So, 21/30 + 28/72 = 49/45
In mixed form: 14/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+28/72 21/30+56/72 21/60+28/72 63/30+28/72 21/30+84/72 21/90+28/72