Add 15/18 and 54/7, Solve 15/18 + 7 5/7 as a fraction

Add 15/18 and 54/7

1^st number: 15/18, 2^nd number: 7 5/7

15/18 + 54/7 is 359/42.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 7 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126
Likewise, for the 2nd fraction, since 7 × 18 = 126,
54/7 = 54 × 18/7 × 18 = 972/126
Add the two like fractions:
105/126 + 972/126 = 105 + 972/126 = 1077/126
1077/126 simplified gives 359/42
So, 15/18 + 54/7 = 359/42
In mixed form: 823/42

MathStep (Works offline)

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