Add 21/45 and 20/40
21/45 + 20/40 is 29/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 45 × 8 = 360,
21/45 = 21 × 8/45 × 8 = 168/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
20/40 = 20 × 9/40 × 9 = 180/360 - Add the two like fractions:
168/360 + 180/360 = 168 + 180/360 = 348/360 - 348/360 simplified gives 29/30
- So, 21/45 + 20/40 = 29/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45+20/40 21/90+20/40 21/45+20/80 63/45+20/40 21/45+60/40