Add 28/21 and 12/45
1st number: 1 7/21, 2nd number: 12/45
28/21 + 12/45 is 8/5.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
28/21 = 28 × 15/21 × 15 = 420/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
12/45 = 12 × 7/45 × 7 = 84/315 - Add the two like fractions:
420/315 + 84/315 = 420 + 84/315 = 504/315 - 504/315 simplified gives 8/5
- So, 28/21 + 12/45 = 8/5
In mixed form: 13/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21+12/45 28/21+24/45 28/42+12/45 28/21+12/90 84/21+12/45 28/21+36/45 28/63+12/45 28/21+60/45 28/21+84/45