Add 27/45 and 15/21, Solve 27/45 + 15/21 as a fraction

Add 27/45 and 15/21

27/45 + 15/21 is 46/35.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
27/45 = 27 × 7/45 × 7 = 189/315
Likewise, for the 2nd fraction, since 21 × 15 = 315,
15/21 = 15 × 15/21 × 15 = 225/315
Add the two like fractions:
189/315 + 225/315 = 189 + 225/315 = 414/315
414/315 simplified gives 46/35
So, 27/45 + 15/21 = 46/35
In mixed form: 111/35

MathStep (Works offline)

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