Add 18/21 and 20/5
1st number: 18/21, 2nd number: 4 0/5
18/21 + 20/5 is 34/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
18/21 = 18 × 5/21 × 5 = 90/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
20/5 = 20 × 21/5 × 21 = 420/105 - Add the two like fractions:
90/105 + 420/105 = 90 + 420/105 = 510/105 - 510/105 simplified gives 34/7
- So, 18/21 + 20/5 = 34/7
In mixed form: 46/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+20/5 18/21+40/5 18/42+20/5 18/21+20/10 54/21+20/5 18/21+60/5 18/63+20/5 18/21+20/15 90/21+20/5 18/21+20/25 18/21+20/35