Add 18/21 and 18/15
1st number: 18/21, 2nd number: 1 3/15
18/21 + 18/15 is 72/35.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 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 15 × 7 = 105,
18/15 = 18 × 7/15 × 7 = 126/105 - Add the two like fractions:
90/105 + 126/105 = 90 + 126/105 = 216/105 - 216/105 simplified gives 72/35
- So, 18/21 + 18/15 = 72/35
In mixed form: 22/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+18/15 18/21+36/15 18/42+18/15 18/21+18/30 54/21+18/15 18/21+54/15 18/63+18/15 18/21+18/45 90/21+18/15 18/21+90/15 18/21+18/75