Add 84/15 and 18/42, Solve 5 9/15 + 18/42 as a fraction

Add 84/15 and 18/42

1^st number: 5 9/15, 2^nd number: 18/42

84/15 + 18/42 is 211/35.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 42 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 15 × 14 = 210,
84/15 = 84 × 14/15 × 14 = 1176/210
Likewise, for the 2nd fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210
Add the two like fractions:
1176/210 + 90/210 = 1176 + 90/210 = 1266/210
1266/210 simplified gives 211/35
So, 84/15 + 18/42 = 211/35
In mixed form: 61/35

MathStep (Works offline)

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