Add 54/3 and 81/42, Solve 18 0/3 + 1 39/42 as a fraction

Add 54/3 and 81/42

1^st number: 18 0/3, 2^nd number: 1 39/42

54/3 + 81/42 is 279/14.

Find the least common denominator or LCM of the two denominators:
LCM of 3 and 42 is 42

Next, find the equivalent fraction of both fractional numbers with denominator 42
For the 1st fraction, since 3 × 14 = 42,
54/3 = 54 × 14/3 × 14 = 756/42
Likewise, for the 2nd fraction, since 42 × 1 = 42,
81/42 = 81 × 1/42 × 1 = 81/42
Add the two like fractions:
756/42 + 81/42 = 756 + 81/42 = 837/42
837/42 simplified gives 279/14
So, 54/3 + 81/42 = 279/14
In mixed form: 1913/14

MathStep (Works offline)

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