Add 21/45 and 4/20
21/45 + 4/20 is 2/3.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
21/45 = 21 × 4/45 × 4 = 84/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
4/20 = 4 × 9/20 × 9 = 36/180 - Add the two like fractions:
84/180 + 36/180 = 84 + 36/180 = 120/180 - 120/180 simplified gives 2/3
- So, 21/45 + 4/20 = 2/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45+4/20 21/45+8/20 21/90+4/20 21/45+4/40 63/45+4/20 21/45+12/20 21/45+4/60 21/45+28/20