Add 9/21 and 20/90
9/21 + 20/90 is 41/63.
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,
9/21 = 9 × 30/21 × 30 = 270/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
20/90 = 20 × 7/90 × 7 = 140/630 - Add the two like fractions:
270/630 + 140/630 = 270 + 140/630 = 410/630 - 410/630 simplified gives 41/63
- So, 9/21 + 20/90 = 41/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/21+20/90 9/21+40/90 9/42+20/90 27/21+20/90 9/21+60/90 9/63+20/90 45/21+20/90 63/21+20/90