Add 15/21 and 35/40
15/21 + 35/40 is 89/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
15/21 = 15 × 40/21 × 40 = 600/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
35/40 = 35 × 21/40 × 21 = 735/840 - Add the two like fractions:
600/840 + 735/840 = 600 + 735/840 = 1335/840 - 1335/840 simplified gives 89/56
- So, 15/21 + 35/40 = 89/56
In mixed form: 133/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+35/40 15/21+70/40 15/42+35/40 15/21+35/80 45/21+35/40 15/63+35/40 75/21+35/40