Add 21/84 and 90/25
1st number: 21/84, 2nd number: 3 15/25
21/84 + 90/25 is 77/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 25 is 2100
Next, find the equivalent fraction of both fractional numbers with denominator 2100 - For the 1st fraction, since 84 × 25 = 2100,
21/84 = 21 × 25/84 × 25 = 525/2100 - Likewise, for the 2nd fraction, since 25 × 84 = 2100,
90/25 = 90 × 84/25 × 84 = 7560/2100 - Add the two like fractions:
525/2100 + 7560/2100 = 525 + 7560/2100 = 8085/2100 - 8085/2100 simplified gives 77/20
- So, 21/84 + 90/25 = 77/20
In mixed form: 317/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84+90/25 21/84+90/50 63/84+90/25 21/84+90/75