Add 20/21 and 25/90
20/21 + 25/90 is 155/126.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
20/21 = 20 × 30/21 × 30 = 600/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
25/90 = 25 × 7/90 × 7 = 175/630 - Add the two like fractions:
600/630 + 175/630 = 600 + 175/630 = 775/630 - 775/630 simplified gives 155/126
- So, 20/21 + 25/90 = 155/126
In mixed form: 129/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/21+25/90 20/21+50/90 20/42+25/90 60/21+25/90 20/21+75/90 20/63+25/90