Add 30/45 and 12/21
30/45 + 12/21 is 26/21.
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,
30/45 = 30 × 7/45 × 7 = 210/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
12/21 = 12 × 15/21 × 15 = 180/315 - Add the two like fractions:
210/315 + 180/315 = 210 + 180/315 = 390/315 - 390/315 simplified gives 26/21
- So, 30/45 + 12/21 = 26/21
In mixed form: 15/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/45+12/21 30/45+24/21 30/90+12/21 30/45+12/42 90/45+12/21 30/45+36/21 30/45+12/63 30/45+60/21 30/45+84/21