Add 8/21 and 75/42, Solve 8/21 + 1 33/42 as a fraction

Add 8/21 and 75/42

1^st number: 8/21, 2^nd number: 1 33/42

8/21 + 75/42 is 13/6.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42

Next, find the equivalent fraction of both fractional numbers with denominator 42
For the 1st fraction, since 21 × 2 = 42,
8/21 = 8 × 2/21 × 2 = 16/42
Likewise, for the 2nd fraction, since 42 × 1 = 42,
75/42 = 75 × 1/42 × 1 = 75/42
Add the two like fractions:
16/42 + 75/42 = 16 + 75/42 = 91/42
91/42 simplified gives 13/6
So, 8/21 + 75/42 = 13/6
In mixed form: 21/6

MathStep (Works offline)

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