Add 80/21 and 14/40, Solve 3 17/21 + 14/40 as a fraction

Add 80/21 and 14/40

1^st number: 3 17/21, 2^nd number: 14/40

80/21 + 14/40 is 1747/420.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 21 × 40 = 840,
80/21 = 80 × 40/21 × 40 = 3200/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
14/40 = 14 × 21/40 × 21 = 294/840
Add the two like fractions:
3200/840 + 294/840 = 3200 + 294/840 = 3494/840
3494/840 simplified gives 1747/420
So, 80/21 + 14/40 = 1747/420
In mixed form: 467/420

MathStep (Works offline)

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