Add 21/70 and 15/72
21/70 + 15/72 is 61/120.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 72 is 2520
Next, find the equivalent fraction of both fractional numbers with denominator 2520 - For the 1st fraction, since 70 × 36 = 2520,
21/70 = 21 × 36/70 × 36 = 756/2520 - Likewise, for the 2nd fraction, since 72 × 35 = 2520,
15/72 = 15 × 35/72 × 35 = 525/2520 - Add the two like fractions:
756/2520 + 525/2520 = 756 + 525/2520 = 1281/2520 - 1281/2520 simplified gives 61/120
- So, 21/70 + 15/72 = 61/120
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70+15/72 21/70+30/72 63/70+15/72 21/70+45/72 21/70+75/72