Add 84/42 and 21/20, Solve 2 0/42 + 1 1/20 as a fraction

Add 84/42 and 21/20

1^st number: 2 0/42, 2^nd number: 1 1/20

84/42 + 21/20 is 61/20.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 42 × 10 = 420,
84/42 = 84 × 10/42 × 10 = 840/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420
Add the two like fractions:
840/420 + 441/420 = 840 + 441/420 = 1281/420
1281/420 simplified gives 61/20
So, 84/42 + 21/20 = 61/20
In mixed form: 31/20

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad