Add 27/21 and 42/49, Solve 1 6/21 + 42/49 as a fraction

Add 27/21 and 42/49

1^st number: 1 6/21, 2^nd number: 42/49

27/21 + 42/49 is 15/7.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 49 is 147

Next, find the equivalent fraction of both fractional numbers with denominator 147
For the 1st fraction, since 21 × 7 = 147,
27/21 = 27 × 7/21 × 7 = 189/147
Likewise, for the 2nd fraction, since 49 × 3 = 147,
42/49 = 42 × 3/49 × 3 = 126/147
Add the two like fractions:
189/147 + 126/147 = 189 + 126/147 = 315/147
315/147 simplified gives 15/7
So, 27/21 + 42/49 = 15/7
In mixed form: 21/7

MathStep (Works offline)

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