Add 84/42 and 18/21
1st number: 2 0/42, 2nd number: 18/21
84/42 + 18/21 is 20/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
84/42 = 84 × 1/42 × 1 = 84/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
18/21 = 18 × 2/21 × 2 = 36/42 - Add the two like fractions:
84/42 + 36/42 = 84 + 36/42 = 120/42 - 120/42 simplified gives 20/7
- So, 84/42 + 18/21 = 20/7
In mixed form: 26/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/42+36/21 84/42+18/42 84/42+54/21 84/42+18/63 84/42+90/21