Add 80/42 and 1/21, Solve 1 38/42 + 1/21 as a fraction

Add 80/42 and 1/21

1^st number: 1 38/42, 2^nd number: 1/21

80/42 + 1/21 is 41/21.

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

Next, find the equivalent fraction of both fractional numbers with denominator 42
For the 1st fraction, since 42 × 1 = 42,
80/42 = 80 × 1/42 × 1 = 80/42
Likewise, for the 2nd fraction, since 21 × 2 = 42,
1/21 = 1 × 2/21 × 2 = 2/42
Add the two like fractions:
80/42 + 2/42 = 80 + 2/42 = 82/42
82/42 simplified gives 41/21
So, 80/42 + 1/21 = 41/21
In mixed form: 120/21

MathStep (Works offline)

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