Add 21/84 and 81/45
1st number: 21/84, 2nd number: 1 36/45
21/84 + 81/45 is 41/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 45 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 84 × 15 = 1260,
21/84 = 21 × 15/84 × 15 = 315/1260 - Likewise, for the 2nd fraction, since 45 × 28 = 1260,
81/45 = 81 × 28/45 × 28 = 2268/1260 - Add the two like fractions:
315/1260 + 2268/1260 = 315 + 2268/1260 = 2583/1260 - 2583/1260 simplified gives 41/20
- So, 21/84 + 81/45 = 41/20
In mixed form: 21/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84+81/45 21/84+81/90 63/84+81/45