Add 80/42 and 28/20, Solve 1 38/42 + 1 8/20 as a fraction

Add 80/42 and 28/20

1^st number: 1 38/42, 2^nd number: 1 8/20

80/42 + 28/20 is 347/105.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 42 × 10 = 420,
80/42 = 80 × 10/42 × 10 = 800/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
28/20 = 28 × 21/20 × 21 = 588/420
Add the two like fractions:
800/420 + 588/420 = 800 + 588/420 = 1388/420
1388/420 simplified gives 347/105
So, 80/42 + 28/20 = 347/105
In mixed form: 332/105

MathStep (Works offline)

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