Add 21/45 and 3/21
21/45 + 3/21 is 64/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
21/45 = 21 × 7/45 × 7 = 147/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
3/21 = 3 × 15/21 × 15 = 45/315 - Add the two like fractions:
147/315 + 45/315 = 147 + 45/315 = 192/315 - 192/315 simplified gives 64/105
- So, 21/45 + 3/21 = 64/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45+3/21 21/45+6/21 21/90+3/21 21/45+3/42 63/45+3/21 21/45+9/21 21/45+3/63 21/45+15/21