Add 84/45 and 21/84, Solve 1 39/45 + 21/84 as a fraction

Add 84/45 and 21/84

1^st number: 1 39/45, 2^nd number: 21/84

84/45 + 21/84 is 127/60.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 84 is 1260

Next, find the equivalent fraction of both fractional numbers with denominator 1260
For the 1st fraction, since 45 × 28 = 1260,
84/45 = 84 × 28/45 × 28 = 2352/1260
Likewise, for the 2nd fraction, since 84 × 15 = 1260,
21/84 = 21 × 15/84 × 15 = 315/1260
Add the two like fractions:
2352/1260 + 315/1260 = 2352 + 315/1260 = 2667/1260
2667/1260 simplified gives 127/60
So, 84/45 + 21/84 = 127/60
In mixed form: 27/60

MathStep (Works offline)

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